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In the past two weeks, I had several discussions with peers in the PLM domain about their experiences.
Some of them I met after a long time again face-to-face at the LiveWorx 2023 event. See my review of the event here: The Weekend after LiveWorx 2023.
And there were several interactions on LinkedIn, leading to a more extended discussion thread (an example of a digital thread ?) or a Zoom discussion (a so-called 2D conversation).
To complete the story, I also participated in two PLM podcasts from Share PLM, where we interviewed Johan Mikkelä (currently working at FLSmidth) and, in the second episode Issam Darraj (presently working at ABB) about their PLM experiences. Less a discussion, more a dialogue, trying to grasp the non-documented aspects of PLM. We are looking for your feedback on these podcasts too.
All these discussions led to a reconfirmation that if you are a PLM practitioner, you need a broad skillset to address the business needs, translate them into people and process activities relevant to the industry and ultimately implement the proper collection of tools.
As a sneaky preview for the podcast sessions, we asked both Johan and Issam about the importance of the tools. I will not disclose their answers here; you have to listen.
Let’s look at some of the discussions.
NOTE: Just before pushing the Publish button, Oleg Shilovitsky published this blog article PLM Project Failures and Unstoppable PLM Playbook. I will comment on his points at the end of this post. It is all part of the extensive discussion.
PLM, LinkedIn and complexity
The most popular discussions on LinkedIn are often related to the various types of Bills of Materials (eBOM, mBOM, sBOM), Part numbering schemes (intelligent or not), version and revision management and the famous FFF discussions.
This post: PLM and Configuration Management Best Practices: Working with Revisions, from Andreas Lindenthal, was a recent example that triggered others to react.
I had some offline discussions on this topic last week, and I noticed Frédéric Zeller wrote his post with the title PLM, LinkedIn and complexity, starting his post with (quote):
I am stunned by the average level of posts on the PLM on LinkedIn.
I’m sorry, but in 2023 :
- Part Number management (significant, non-significant) should no longer be a problem.
- Revision management should no longer be a question.
- Configuration management theory should no longer be a question.
- Notions of EBOMs, MBOMs … should no longer be a question.
So why are there still problems on these topics?
You can see from the at least 40+ comments that this statement created a lot of reactions, including mine. Apparently, these topics are touching many people worldwide, and there is no simple, single answer to each of these topics. And there are so many other topics relevant to PLM.
Talking later with Frederic for one hour in a Zoom session, we discussed the importance of the right PLM data model.
I also wrote a series about the (traditional) PLM data model: The importance of a (PLM) data model.
Frederic is more of a PLM architect; we even discussed the wording related to the EBOM and the MBOM. A topic that I feel comfortable discussing after many years of experience seeing the attempts that failed and the dreams people had. And this was only one aspect of PLM.
You also find the discussion related to a PLM certification in the same thread. How would you certify a person as a PLM expert?
There are so many dimensions to PLM. Even more important, the PLM from 10-15 years ago (more of a system discussion) is no longer the PLM nowadays (a strategy and an infrastructure) –
This is a crucial difference. Learning to use a PLM tool and implement it is not the same as building a PLM strategy for your company. It is Tools, Process, People versus Process, People, Tools and Data.
Time for Methodology workshops?
I recently discussed with several peers what we could do to assist people looking for best practices discussion and lessons learned. There is a need, but how to organize them as we cannot expect this to be voluntary work.
In the past, I suggested MarketKey, the organizer of the PI DX events, extend its theme workshops. For example, instead of a 45-min Focus group with a short introduction to a theme (e.g., eBOM-mBOM, PLM-ERP interfaces), make these sessions last at least half a day and be independent of the PLM vendors.
Apparently, it did not fit in the PI DX programming; half a day would potentially stretch the duration of the conference and more and more, we see two days of meetings as the maximum. Longer becomes difficult to justify even if the content might have high value for the participants.
I observed a similar situation last year in combination with the PLM roadmap/PDT Europe conference in Gothenburg. Here we had a half-day workshop before the conference led by Erik Herzog(SAAB Aeronautics)/ Judith Crockford (Europstep) to discuss concepts related to federated PLM – read more in this post: The week after PLM Roadmap/PDT Europe 2022.
It reminded me of an MDM workshop before the 2015 Event, led by Marc Halpern from Gartner. Unfortunately, the federated PLM discussion remained a pretty Swedish initiative, and the follow-up did not reach a wider audience.
And then there are the Aerospace and Defense PLM action groups that discuss moderated by CIMdata. It is great that they published their findings (look here), although the best lessons learned are during the workshops.
However, I also believe the A&D industry cannot be compared to a mid-market machinery manufacturing company. Therefore, it is helpful for a smaller audience only.
And here, I inserted a paragraph dedicated to Oleg’s recent post, PLM Project Failures and Unstoppable PLM Playbook – starting with a quote:
How to learn to implement PLM? I wrote about it in my earlier article – PLM playbook: how to learn about PLM? While I’m still happy to share my knowledge and experience, I think there is a bigger need in helping manufacturing companies and, especially PLM professionals, with the methodology of how to achieve the right goal when implementing PLM. Which made me think about the Unstoppable PLM playbook ©.
I found a similar passion for helping companies to adopt PLM while talking to Helena Gutierrez. Over many conversations during the last few months, we talked about how to help manufacturing companies with PLM adoption. The unstoppable PLM playbook is still a work in progress, but we want to start talking about it to get your feedback and start the conversation.
It is an excellent confirmation of the fact that there is a need for education and that the education related to PLM on the Internet is not good enough.
As a former teacher in Physics, I do not believe in the Unstoppable PLM Playbook, even if it is a branded name. Many books are written by specific authors, giving their perspectives based on their (academic) knowledge.
Are they useful? I believe only in the context of a classroom discussion where the applicability can be discussed,
Therefore my questions to vendor-neutral global players, like CIMdata, Eurostep, Prostep, SharePLM, TCS and others, are you willing to pick up this request? Or are there other entities that I missed? Please leave your thoughts in the comments. I will be happy to assist in organizing them.
There are many more future topics to discuss and document too.
- What about the potential split of a PLM infrastructure between Systems of Record & Systems of Engagement?
- What about the Digital Thread, a more and more accepted theme in discussions, but what is the standard definition?
- Is it traceability as some vendors promote it, or is it the continuity of data, direct usable in various contexts – the DevOps approach?
Who likes to discuss methodology?
When asking myself this question, I see the analogy with standards. So let’s look at the various players in the PLM domain – sorry for the immense generalization.
Strategic consultants: standards are essential, but spare me the details.
Vendors: standards are limiting the unique capabilities of my products
Implementers: two types – Those who understand and use standards as they see the long-term benefits. Those who avoid standards as it introduces complexity.
Companies: they love standards if they can be implemented seamlessly.
Universities: they love to explore standards and help to set the standards even if they are not scalable
Just replace standards with methodology, and you see the analogy.
We like to discuss the methodology.
As I mentioned in the introduction, I started to work with Share PLM on a series of podcasts where we interview PLM experts in the field that have experience with the people, the process, the tools and the data side. Through these interviews, you will realize PLM is complex and has become even more complicated when you consider PLM a strategy instead of a tool.
We hope these podcasts might be a starting point for further discussion – either through direct interactions or through contributions to the podcast. If you have PLM experts in your network that can explain the complexity of PLM from various angles and have the experience. Please let us know – it is time to share.
Conclusion
By switching gears, I noticed that PLM has become complex. Too complex for a single person to master. With an aging traditional PLM workforce (like me), it is time to consolidate the best practices of the past and discuss the best practices for the future. There are no simple answers, as every industry is different. Help us to energize the PLM community – your thoughts/contributions?
Announcing PLM Road Map & PDT EMEA 2023
I am writing this post because one of my PLM peers recently asked me this question: “Is the BOM losing its position? He was in discussion with another colleague who told him:
“If you own the BOM, you own the Product Lifecycle”.
This statement made me think of ä recent post from Jan Bosch recent post: Product Development fallacy #8: the bill of materials has the highest priority.
Software becomes increasingly an essential part of the final product, and combined with Jan’s expertise in software development, he wrote this article. I recommend reading the full post (4 min read) and next browse through the comments.
If you cannot afford these 10 minutes, here is my favorite quote from the article:
An excessive focus on the bill of materials leads to significant challenges for companies that are undergoing a digital transformation and adopting continuous value delivery. The lack of headroom, high coupling and versioning hell may easily cause an explosion of R&D expenditure over time.
Where did the BOM focus come from? A historical overview related to the rise (and fall) of the BOM.
In the beginning, there was the drawing.
Before the era of computers, there was “THE drawing”, describing assemblies, subassemblies or parts. And on the drawing, you can find the parts list if relevant. This parts list was the first Bill of Material, describing the parts/materials shown on the drawing.
Next came MRP/ERP
With the introduction of the MRP system (Material Requirement Planning), it was the first step that by using computers, people could collect the material requirements for one system as data and process. Entering new materials/parts described on drawings was still a manual process, as well as referring to existing parts on the drawing. Reuse of parts was a manual process based on individual knowledge.
In the nineties, MRP evolved into ERP (Enterprise Resource Planning), which included the MRP part and added resource and manufacturing planning and financial reporting.
The ERP system became the most significant IT system, the execution system of the company. As it was the first enterprise system implemented, it was the first moment we learned about implementation challenges – people change and budget overruns. However, as the ERP system brought visibility to the company’s execution, it became a “must-have” system for management.
The introduction of mainstream 2D CAD did not affect the company’s culture so much. Drawings became electronic drawings, and the methodology of the parts list on the drawing remained.
Sometimes the interaction with the MRP/ERP system was enhanced by an interface – sending the drawing BOM to ERP. The advantage of the interface: no manual transfer of data reducing typos and BOM errors. The disadvantages at that time: relatively expensive (connectivity between systems was a challenge) and mostly one direction.
And then there was PDM.
In parallel with the introduction of ERP systems, mainstream 3D CAD systems became affordable, particularly SolidWorks, Solid Edge and Inventor. These 3D CAD systems allow sharing of parts and assemblies in different products, and the PDM database was the first aid to support part reuse, versioning and standardization.
By extracting the parts from the assemblies and subassemblies, it was possible to generate a BOM structure in the PDM system to be transferred or typed into the ERP system. We did not talk about EBOM or MBOM then, as there was only one BOM in the ERP system, and the PDM system was a tool to feed the ERP system.
Many companies still have based their processes on this approach. ERP (read SAP nowadays) is the central execution system, and PDM is an external system. You might remember the story and image from my previous post about people, processes and tools. The bad practice example: Asking the ERP system to provide a part number when starting to design a part.
And then products started to change.
In the early 2000s, I worked with SmarTeam to define the E&E (Electronics and Electrical) template. One of the new concepts was to synchronize all design data coming from different disciplines to a single BOM structure.
It was the time we started to talk about the EBOM. A type of BOM, as the structure to consolidate all the design data, was based on parts.
The EBOM, most of the time, reflects the design intent in logical groups and sending the relevant parts in the correct order to the ERP system was a favorite expensive customization for service providers. How to transfer an engineering BOM view to an ERP system that only understands the manufacturing view?
Note: not all ERP systems have the data model to differentiate between engineering parts and manufacturing parts
The image below illustrates the challenge and the customer’s perception. 
The automated link between the design side (EBOM) and manufacturing side (MBOM) was a mission impossible – too many exceptions for the (spaghetti) code.
And then came the MBOM.
The identified issues connecting PDM and ERP led to the concept of implementing the MBOM in the PLM system. The MBOM in PLM is one of the characteristics of a PLM implementation compared to a PDM implementation. In a traditional PLM system, there is an interaction and connection between the EBOM and MBOM. EBOM parts should end up as MBOM parts. This interaction can be supported by automation, however, as it is in the same system, still leaving manual changes possible.
The MBOM structure in PLM could then be the information structure to transfer to the ERP system; however, there is more, as Jörg W. Fischer wrote in his provoking post-Die MBOM muss weg (The MBOM must go). He rightly points out (in German) that the MBOM is not a structure on its own but a combination of different views based on Assembly Drawings, Process Planning and Material Requirements.
His conclusion:
Calling these structures, MBOM is trying to squeeze all three structures into one. That usually doesn’t work and then leads to much more emotional discussions in the project. It also costs a lot of money. It is, therefore, better not to use the term MBOM at all.
And indeed, just having an MBOM in your PLM system might help you to prepare some of the manufacturing steps, the needed resources and parts. The MBOM result still has to be localized at the local plant where the manufacturing takes place. And here, the systems used are the ERP system and the MES system.
The main advantage of having the MBOM in the PLM system is the direct relation between specification and manufacturing intent, allowing manufacturing engineering to work collaboratively with engineering in the same environment.
- The first benefit is fewer iterations and a shorter time to production, thanks to early interaction and manufacturing involvement in the engineering process.
- The second benefit is: product knowledge is centralized in a single system. Consolidating your Product Knowledge in ERP does not make sense due to global localization and the missing capabilities to manage the iterative engineering processes on non-existing parts.
And then came the SBOM, the xBOM
Traditional PLM vendors and implementations kept using xBOM structures as placeholders for related specification data (mechanical designs, electrical, software deliverables, serialized products). Most of the time, related files.
And with this approach, talking about digital thread, PLM systems also touch on the concepts of Configuration Management.
I will not go into the details here but look at the two images by clicking on them and see a similar mindset.
It is about the traceability of information in structures and systems. These structures work well in a relatively static and linear product development and delivery environment, as illustrated below:
Engineering change and release processes are based on managing the changes in different structures from the left to the right.
And then came software!
Modern connected products are no longer mechanical products. The product’s functionality no longer depends on the mechanical properties but mainly on embedded electronics and software used. For example, look at the mechanical design of a telecom transmission tower – its behavior merely comes from non-mechanical components, and they can change over time. Still, the Bill of Material contains a lot of concrete and steel parts.
The ultimate example is comparing a Tesla (software on wheels) with a traditional car. For modern connected products, electronics and software need to be part of the solution. Software and electronics allow the product to be upgraded over time. Managing these products in the same manner as mechanical products is impossible, inefficient and therefore threatening your company’s future business.
I requote Jan Bosch:
An excessive focus on the bill of materials leads to significant challenges for companies that are undergoing a digital transformation and adopting continuous value delivery. The lack of headroom, high coupling and versioning hell may easily cause an explosion of R&D expenditure over time.
The model-based, connected enterprise
I will not solve the puzzle of the future in this post. You can read my observations in my series: The road to model-based and connected PLM. We need a new infrastructure with at least two modes. One that still serves as a System of Record, storing information in a traditional manner, like a Bill of Materials for the static parts, as not everyone and everything can be connected.
In addition, we need various Systems of Engagement that enable close to real-time interaction between products (systems) and relevant stakeholders for the engagement scope(multidisciplinary / consumers).
Digital twins are examples of such environments. Currently, these Systems of Engagement often work disconnected from the System of Record due to the lack of understanding of how to connect. (standard connectors? / OSLC?)
Our mission is to explore, as I wrote in my post Time to split PLM and drop our mechanical mindset.
And while I was finalizing this post, I read a motivating post from Jan Bosch again for all of you working on understanding and pushing the digital transformation in your eco-system.
The title: Be the protagonist of your life: 15 rules A starting point for more to come.
Conclusion
The BOM is no longer the master of the product lifecycle when it comes to managing connected products, where functionality mainly depends on software. BOM structures with related documents are just one of the extracted baselines from a data-driven, connected enterprise. This traditional PLM infrastructure requires other, non-BOM-driven structures to represent the actual status of a virtual or physical product.
The BOM is not dead, but there is more ………
Your thoughts?
In the series learning from the past to understand the future, we have almost reached the current state of PLM before digitization became visible. In the last post, I introduced the value of having the MBOM preparation inside a PLM-system, so manufacturing engineering can benefit from early visibility and richer product context when preparing the manufacturing process.
Does everyone need an MBOM?
It is essential to realize that you do not need an EBOM and a separate MBOM in case of an Engineering To Order primary process. The target of ETO is to deliver a unique customer product with no time to lose. Therefore, engineering can design with a manufacturing process in mind.
The need for an MBOM comes when:
- You are selling a specific product over a more extended period of time. The engineering definition, in that case, needs to be as little as possible dependent on supplier-specific parts.
- You are delivering your portfolio based on modules. Modules need to be as long as possible stable, therefore independent of where they are manufactured and supplier-specific parts. The better you can define your modules, the more customers you can reach over time.
- You are having multiple manufacturing locations around the world, allowing you to source locally and manufacture based on local plant-specific resources. I described these options in the previous post
The challenge for all companies that want to move from ETO to BTO/CTO is the fact that they need to change their methodology – building for the future while supporting the past. This is typically something to be analyzed per company on how to deal with the existing legacy and installed base.
Configurable EBOM and MBOM
In some previous posts, I mentioned that it is efficient to have a configurable EBOM. This means that various options and variants are managed in the same EBOM-structure that can be filtered based on configuration parameters (date effectivity/version identifier/time baseline). A configurable EBOM is often called a 150 % EBOM
The MBOM can also be configurable as a manufacturing plant might have almost common manufacturing steps for different product variants. By using the same process and filtered MBOM, you will manufacture the specific product version. In that case, we can talk about a 120 % MBOM
Note: the freedom of configuration in the EBOM is generally higher than the options in the configurable MBOM.
The real business change for EBOM/MBOM
So far, we have discussed the EBOM/MBOM methodology. It is essential to realize this methodology only brings value when the organization will be adapted to benefit from the new possibilities. 
One of the recurring errors in PLM implementations is that users of the system get an extended job scope, without giving them the extra time to perform these activities. Meanwhile, other persons downstream might benefit from these activities. However, they will not complain. I realized that already in 2009, I mentioned such a case: Where is my PLM ROI, Mr. Voskuil?
Now let us look at the recommended business changes when implementing an EBOM/MBOM-strategy
- Working in a single, shared environment for engineering and manufacturing preparation is the first step to take.
Working in a PLM-system is not a problem for engineers who are used to the complexity of a PDM-system. For manufacturing engineers, a PLM-environment will be completely new. Manufacturing engineers might prepare their bill of process first in Excel and ultimately enter the complete details in their ERP-system. ERP-systems are not known for their user-friendliness. However, their interfaces are often so rigid that it is not difficult to master the process. Excel, on the other side, is extremely flexible but not connected to anything else.
And now, this new PLM-system requires people to work in a more user-friendly environment with limited freedom. This is a significant shift in working methodology. This means manufacturing engineers need to be trained and supported over several months. Changing habits and keep people motivated takes energy and time. In reality, where is the budget for these activities? See my 2016 post: PLM and Cultural Change Management – too expensive?
- From sequential to concurrent
Once your manufacturing engineers are able to work in a PLM-environment, they are able to start the manufacturing definition before the engineering definition is released. Manufacturing engineers can participate in design reviews having the information in their environment available. They can validate critical manufacturing steps and discuss with engineers potential changes that will reduce the complexity or cost for manufacturing. As these changes will be done before the product is released, the cost of change is much lower. After all, having engineering and manufacturing working partially in parallel will reduce time to market.
Reducing time to market by concurrent engineering
One of the leading business drivers for many companies is introducing products or enhancements to the market. Bringing engineering and manufacturing preparation together also means that the PLM-system can no longer be an engineering tool under the responsibility of the engineering department.
The responsibility for PLM needs to be at a level higher in the organization to ensure well-balanced choices. A higher level in the organization automatically means more attention for business benefits and less attention for functions and features.
From technology to methodology – interface issues?
The whole EBOM/MBOM-discussion often has become a discussion related to a PLM-system and an ERP-system. Next, the discussion diverted to how these two systems could work together, changing the mindset to the complexity of interfaces instead of focusing on the logical flow of information.
In an earlier PI Event in München 2016, I lead a focus group related to the PLM and ERP interaction. The discussion was not about technology, all about focusing on what is the logical flow of information. From initial creation towards formal usage in a product definition (EBOM/MBOM).
What became clear from this workshop and other customer engagements is that people are often locked in their siloed way of thinking. Proposed information flows are based on system capabilities, not on the ideal flow of information. This is often the reason why a PLM/ERP-interface becomes complicated and expensive. System integrators do not want to push for organizational change, they prefer to develop an interface that adheres to the current customer expectations.
SAP has always been promoting that they do not need an interface between engineering and manufacturing as their data management starts from the EBOM. They forgot to mention that they have a difficult time (and almost no intention) to manage the early ideation and design phase. As a Dutch SAP country manager once told me: “Engineers are resources that do not want to be managed.” This remark says all about the mindset of ERP.
After overlooking successful PLM-implementations, I can tell the PLM-ERP interface has never been a technical issue once the methodology is transparent. A company needs to agree on logical data flow from ideation through engineering towards design is the foundation.
It is not about owning data and where to store it in a single system. It is about federated data sets that exist in different systems and that are complementary but connected, requiring data governance and master data management.
The SAP-Siemens partnership
In the context of the previous paragraph, the messaging around the recently announced partnership between SAP and Siemens made me curious. Almost everyone has shared an opinion about the partnership. There is a lot of speculation, and many questions were imaginarily answered by as many blog posts in the field. Last week Stan Przybylinski shared CIMdata’s interpretations in a webinar Putting the SAP-Siemens Partnership In Context, which was, in my opinion, the most in-depth analysis I have seen.
For what it is worth, my analysis:
- First of all, the partnership is a merger of slide decks at this moment, aiming to show to a potential customer that in the SAP/Siemens-combination, you find everything you need. A merger of slides does not mean everything works together.
- It is a merger of two different worlds. You can call SAP a real data platform with connected data, where Siemens offering is based on the Teamcenter backbone providing a foundation for a coordinated approach. In the coordinated approach, the data flexibility is lower. For that reason, Mendix is crucial to make Siemens portfolio behave like a connected platform too.
You can read my doubts about having a coordinated and connected system working together (see image above). It was my #1 identified challenge for this decade: PLM 2020 – PLM the next decade (before COVID-19 became a pandemic and illustrated we need to work connected) - The fact that SAP will sell TC PLM and Siemens will sell SAP PPM seems like loser’s statement, meaning our SAP PLM is probably not good enough, or our TC PPM capabilities are not good enough. In reality, I believe they both should remain, and the partnership should work on logical data flows with data residing in two locations – the federated approach. This is how platforms reside next to each other instead of the single black hole.
- The fact that standard interfaces will be developed between the two systems is a subtle sales argument with relatively low value. As I wrote in the “from technology to methodology”-paragraph, the challenges are in the organizational change within companies. Technology is not the issue, although system integrators also need to make a living.
- What I believe makes sense is that both SAP and Siemens, have to realize their Industry 4.0 end-to-end capabilities. It is a German vision now for several years and it is an excellent vision to strive for. Now it is time to build the two platforms working together. This will be a significant technical challenge mainly for Siemens as its foundation is based on a coordinated backbone.
- The biggest challenge, not only for this partnership, is the organizational change within companies that want to build an end-to-end connected solution. In particular, in companies with a vast legacy, the targeted industries by the partnership, the chasm between coordinated legacy data and intended connected data is enormous. Technology will not fix it, perhaps smoothen the pain a little.
Conclusion
With this post, we have reached the foundation of the item-centric approach for PLM, where the EBOM and MBOM are managed in a real-time context. Organizational change is the biggest inhibitor to move forward. The SAP-Siemens partnership is a sales/marketing approach to create a simplified view for the future at C-level discussions.
Let us watch carefully what happens in reality.
Next time potentially the dimension of change management and configuration management in an item-centric approach.
Or perhaps Martijn Dullaart will show us the way before, following up on his tricky poll question
Already five posts since we started looking at the roots of PLM, where every step illustrated that new technical capabilities could create opportunities for better practices. Alternatively, sometimes, these capabilities introduced complexity while maintaining old practices. Where the previous posts were design and engineering-centric, now I want to make the step moving to manufacturing-preparation and the MBOM. In my opinion, if you start to manage your manufacturing BOM in the context of your product design, you are in the scope of PLM.
For the moment, I will put two other related domains aside, i.e., Configuration Management and Configured Products. Note these domains are entirely different from each other.
Some data model principles
In part five, I introduced the need to have a split between a logical product definition and a technical EBOM definition. The logical product definition is more the system or modular structure to be used when configuring solutions for a customer. The technical EBOM definition is, most of the time, a stable engineering specification independent of how and where the product is manufactured. The manufacturing BOM (the MBOM) should represent how the product will be manufactured, which can vary per location and vary over time. Let us look in some of the essential elements of this data model
The Product
The logical definition of the product, which can also be a single component if you are a lower tier-supplier, has an understandable number, like 6030-10B. A customer needs to be able to order this product or part without a typo mistake. The product has features or characteristics that are used to sell the product. Usually, products do not have a revision, as it is a logical definition of a set of capabilities. Most of the time, marketing is responsible for product definition. This would be the sales catalog, which can be connected in a digital PLM environment. Like the PDM-ERP relation, there is a similar discussion related to where the catalog resides—more on the product side later in time.
The EBOM
Related to the product or component in the logical definition, there is an actual EBOM, which represents the technical specification of the product. The image above shows the relation represented by the blue “current” link.
Note: not all systems will support such a data model, and often the marketing sides in managed disconnected from the engineering side. Either in Excel or in a specialized Product Line Engineering (PLE) tools.
We discussed in the previous post that if you want to minimize maintenance, meaning fewer revisions on your EBOM, you should not embed manufacturer-specific parts in your EBOM.
The EBOM typically contains purchase parts and make parts. The purchased parts are sourced based on their specification, and you might have a single source in the beginning. The make parts are entirely under your engineering control, and you define where they are produced and by whom. For the rest, the EBOM might have functional groupings of modules and subassemblies that are defined for reuse by engineering.
Note: An EBOM is the place where multidisciplinary collaboration comes together. This post mainly deals with the mechanical part (as we are looking at the past)
Note: An EBOM can contain multiple valid configurations which you can filter based on a customer or market-specific demand. In this case, we talk about a Configured EBOM or a 150 % EBOM.
The MBOM
The MBOM represents the way the unique product is going to be manufactured. This means the MBOM-structure will represent the manufacturing steps. For each EBOM-purchase-part, the approved manufacturer for that plant needs to be selected. For each make-part in the EBOM, if made in this plant per customer order, the EBOM parts need to be resolved by one or more manufacturing steps combined with purchased materials.
Let us look at some examples:
The flat MBOM
Some companies do not have real machinery anymore in their plants, the product they deliver to the market is only assembled at the best financial location. This means that all MBOM-parts should arrive at the shop floor to be assembled there. As an example, we have plant A below.
Of course, this is a simplified version to illustrate the basics of the MBOM. The flat MBOM only makes sense if the product is straightforward to assemble. Based on the engineering specifications, the assembly drawing(s) people on the shop floor will know what to do.
The engineering definition specifies that the chassis needs to be painted, and fitting the axles requires grease. These quantities are not visible in the EBOM; they will appear in the MBOM. The quantities and the unit of measure are, of course, relevant here.
Note: The exact quantities for paint and grease might be adjusted in the MBOM when a series of Squads have been manufactured.
The MBOM and Bill of Process
Most of the time, a product is manufactured in several process steps. For that reason, the MBOM is closely related to the Bill of Process or the Routing definitions. The image below illustrates the relationship between an MBOM and the operations in a plant.
If we continue with our example of the Squad, let us now assume that the wheels and the axle are joined together in a work cell. In addition, the chassis is painted in a separate cell. The MBOM would look like the image below:
In the image, we see that the same Engineering definition now results in a different MBOM. A company can change the MBOM when optimizing the production, without affecting the engineering definition. In this MBOM, the Axle assembly might also be used in other squads manufactured by the company.
The MBOM and purchased parts
In the previous example, all components for the Squad were manufactured by the same company with the option to produce in Plant A or in Plant B. Now imagine the company also has a plant C in a location where they cannot produce the wheels and axle assembly. Therefore plant C has to “purchase” the Wheel-Axle assembly, and lucky for them plant B is selling the Wheel+Axle assembly to the market as a product.
The MBOM for plant C would look like the image below:
For Plant C, they will order the right amount of the Wheel+Axle product, according to its specifications (HF-D240). How the Wheel+Axle product is manufactured is invisible for Plant C, the only point to check is if the Wheel+Axle product complies with the Engineering Definition and if its purchase price is within the target price range.
Why this simple EBOM-MBOM story?
For those always that have been active in the engineering domain, a better understanding of the information flow downstream to manufacturing is crucial. Historically this flow of information has been linear – and in many companies, it is still the fact. The main reason for that lies in the fact that engineering had their own system (PDM or PLM), and manufacturing has their own system (ERP).
Engineers did their best to provide the best engineering specification and release the data to ERP. In the early days, as discussed in Part 4, the engineering specification was most of the time based on a kind of hybrid BOM containing engineering and manufacturing parts already defined.
Next, manufacturing engineering uses the engineering specifications to define the manufacturing BOM in the ERP system. Based on the drawings and parts list, they create a preferred manufacturing process (MBOM and BOP) – most of the time, a manual process. Despite the effort done by engineering, there might be a need to change the product. A different shape or dimension make manufacturing more efficient or done with existing tooling. This means an iteration, which causes delays and higher engineering costs.
The first optimization invented was the PDM-ERP interface to reduce the manual work and introduction of typos/misunderstanding of data. This topic was “hot” between 2000 and 2010, and I visited many SmarTeam customers and implementers to learn and later explain that this is a mission impossible. The picture below says it all.
We have an engineering BOM (with related drawings). Through an interface, this EBOM will be restructured into a manufacturing BOM, thanks to all kinds of “clever” programming based on particular attributes. Discussed in Part 3
The result, however, was that the interface was never covering all situations and became the most expensive part of the implementation.
Good business for the implementing companies, bad for the perception of PDM/PLM.
The lesson learned from all these situations: If you have a PLM-system that can support both the EBOM and MBOM in the same environment, you do not need this complex interface anymore. You can still use some automation to move from an EBOM to an MBOM.
However, three essential benefits come from this approach
- Working in a single environment allows manufacturing engineers to work directly in the context of the EBOM, proposing changes to engineering in the same environment and perform manual restructuring on the MBOM as programming logic does not exist. Still, compare tools will ensure all EBOM-parts are resolved in the manufacturing definition.
- All product Intellectual Property is now managed in a single environment. There is no scattered product information residing in local ERP-systems. When companies moved towards multiple plants for manufacturing, there was the need for a centralized generic MBOM to be resolved for the local plant (local suppliers / local plant conditions). Having the generic MBOM and Bill of Process in PLM was the solution.
- When engineers and manufacturing engineers work in the same environment, manufacturing engineering can start earlier with the manufacturing process definition, providing early feedback to engineering even when the engineering specification has not been released. This approach allows real concurrent engineering, reducing time to market and cost significantly
Conclusion
Again 1600 words this time. We are now at the stage that connecting the EBOM and the MBOM in PLM has become a best practice in most standard PLM-systems. If implemented correctly, the interface to ERP is no longer on the critical path – the technology never has been the limitation – it is all about methodology.
Next time a little bit more on advanced EBOM/MBOM interactions
In this post in the series Learning from the past to understand the future, I want to leave the 3D CAD structures behind. But before doing so, I want to mention some of the lessons learned:
In Part 1: “Intelligent” drawing numbers were the source for “intelligent” part numbers as often there was a one-to-one relationship between the drawing and the part(s) on a drawing.
In Part 2: 3D CAD has been introduced in the automotive and aerospace industry due to process optimization, where a 3D CAD environment created better collaboration possibilities (DMU). The introduction of 3D CAD in the mid-market was different. Here 3D CAD is used as an engineering tool, not changing any processes.
The complexity grew because also file names needed to be managed, introducing the need for PDM-systems.
In Part 3: we discussed the challenges of working with file-based 3D CAD structures. The versioning problem with check-in/check-out of structure in particular in the case of data reuse. Here the best practice was introduced to have physical parts with a different lifecycle than 3D CAD parts and assemblies.
Now engineers need to create valid configurations based on links between the physical part and the 3D/2D object. This requires a PDM-system with BOM and CAD-files as standard information objects.
In Part 4: we discussed the relations between the BOM and 3D CAD structures without neglecting the fact the 2D Drawing is still the primary legal information carrier for manufacturing/suppliers. The point discussed in this post was the fact that most companies used a kind of ETO-approach. Starting from the 3D CAD-system, adding sometimes manufacturing parts in this structure, to generate a BOM that can be served as input for the ERP-system.
I want to follow up from the last conclusion:
Changing from ETO to CTO requires modularity and a BOM-driven approach. Starting from a 3D CAD-structure can still be done for the lowest levels – the modules, the options. In a configure to order process, it might not be relevant anymore to create a full 3D-representation of the product.
Starting from a conceptual structure
Most companies that deliver products to the market do not start from scratch, as we discussed. They will start from either copying an existing product definition (not recommend) or trying to manage the differences between them, meanwhile keeping shared components under revision control.
This cannot be done based on 3D CAD-structures anymore. At that time (we are in the early 2000s) in the mid-market, the PDM-system was used to manage these structures, in particular, they used the BOM-capabilities.
The BOM-structure was often called the EBOM, as engineers were defining the EBOM. But is it really an EBOM? Let us have a look wat defines an EBOM.
What characterizes an EBOM?
There are many personal definitions of what is considered as an EBOM. Also, the Wiki-definition here does not help us a lot. So here is my personal 2004 definition:
- The EBOM reflects the engineering view of a product and, therefore, can have a logical structure of assemblies and subassemblies based on functionality, modularity, and standardization.
- The EBOM is a part structure specifying a product from its design intent, specifying parts, materials, tolerances, finishing.
- The EBOM-structure is allowing multidisciplinary teams to work together on a joint definition of the product
The picture below illustrates the above definition.
In this EBOM-structure, we see that the first two levels actually are more a logical division of functional groups, either as units, product/discipline-specific definitions (cabling/software). These components should not be in the EBOM if you have support for logical structures in your PLM-environment. However, in 2004 – PLM was not that mature in the mid-market, and this approach was often chosen.
If we look at the Line Feed module, which could also be used in other products, there is the typical mechanical definition and in parallel the electrical definition. Having them inside a single EBOM gives the advantage of being able to do a “where-used” and status/impact-analysis.
1 – Purchased parts
Motor P280 is an interesting EBOM-part to consider. This motor is required; however, in an EBOM, you should not specify the supplier part number directly. As supplier part availability and preference will change over time, you do not want to revise the EBOM every time a supplier part gets changed.
Therefore, the Motor P280 should have an internal part number in the EBOM. Next, it will be engineering that specifies which motors fulfill the need for Motor P280. Preferably they will create an Approved Manufacturing List for this motor to give manufacturing/purchasing the flexibility to decide per order where to purchase the motor and from which supplier.
The relation between the Approved Manufacturing List and the Approved Vendor List is shown in the diagram above.
Or follow the link to this image to read more in Arena’s glossary. In particular, for electronic components, this concept is needed as high-level specifications for electronic parts might be the same.
However, the details (tolerances/environment) can be decisive, which component is allowed. Besides, due to the relatively short lifecycle of electronic components, the EBOM needs to be designed in such a manner to anticipate changes in suppliers.
You can only benefit from this approach if, from the beginning of your designs, there are no supplier-specific parts in your EBOM. For Engineering, to Order companies that want to become more Build to Order, this is a challenging but critical point to consider.
Note: The functional characteristics for the motor will come from the electrical definition, and through a reference designator, we create the link between the functional definition and the physical implementation in the product.
2 – Make Parts
Secondly, if we look to the conveyor block D1020 rev A, this block is a make part, with probable a whole assembly of parts below it. As it is a make part, there is at least an assembly drawing and, more likely, a related technical data package linked to D1020 rev A. Make parts still carry a revision as here the Form-Fit-Function discussion can be used when implementing a change of the part.
Note: I used for the final assembly drawing the same number scheme as this is how most companies work. However, in my previous post, I described that if you have a PDM-system in place, the numbering can be different. Maintaining the relations between a part and the related drawing is, in this case, crucial.
The Configured EBOM
The image on the left, we used to illustrate the typical mid-market EBOM in a PDM-system, will become more complicated if we also add options and variants to the EBOM. I assume you know the difference between a variant and an option.
In this case, the EBOM the definition for the full product range. Actually, the top part of the EBOM does not exist as an instance. It is the placeholder to select a resolved EBOM for a specific product configuration. For the ease of use, I have simplified the initial diagram, now zooming in on variants and options, apologizing for my artistic capabilities as the purpose of a blog is different from a book.
If we look at the diagram, this configured structure contains variants and options.
First, on the logical definition, we see a new grouping. There are two types of Line Feed available, one specific for the X-123 and a later, more generic designed LF100, suitable for all X-1nn variants.
As the LF100 is more generic designed, the customer can select between two motors, the standard P280 and the more advanced version P360, with better service capabilities.
For the Line Feed LF200, there is an option to order a Noise Reduction Cover. It was sold once to an existing customer, and as the cover fits all X-123, it has been linked here as an option to the X-123 definition. So, the customer solution with the Noise Reduction Cover does not have an isolated, copied structure in the EBOM.
Also, in the Logical Structure, we see there is a cabling definition for the X-123 or the default cabling set for all other products.
The diagram illustrates what many mid-market companies have been doing more or less in their PDM-system to avoid copying of EBOM structures per customer order.
It is an example of where a tool (the PDM-system) is slowly abused for administrative reasons. Let me explain why.
The link between Products and (E)BOMs
If we look at the upper part of the configured EBOM structure, this is a logical product definition. Or to say it in different words, it is a portfolio definition, which products and modules a company can sell to the market. Some of the grouping of the portfolio is purely based on business reasons, which products and options do we want to sell.
In most companies, the product portfolio is managed in (marketing) documents without a direct connection to the engineering world. However, we will see in an upcoming post, this relation is crucial for a digital enterprise. Meanwhile, look at on old blog post: Products, BOMs and Parts if you want to be faster
The Engineering definition below the red dashed line is a real EBOM, representing the engineering definition of a system, a module, or a component. When these systems and modules are defined in a single structure that can be filtered based on selection criteria, we talk about a Configured EBOM or sometimes a 150 % EBOM.
Each of the components in the configured EBOM can have a related 3D CAD structure or specification that can be developed traditionally.
The result of a resolved EBOM is a variant that can be delivered to the customer. In this EBOM-driven approach, there is not always a full 3D-representation of the customer product.
Again, size (1500+) words make me stop this story, where next time we will go from product to EBOM and introduce the need for an MBOM in specific industries.
Conclusion
A pure EBOM only specifies a product and contains all relevant information in context – designs & specifications. The EBOM should not be mixed or confused with a logical grouping, belonging to a portfolio definition (even if the system allows you to do it)
On my previous post shared on LinkedIn Ilan Madjar, a long-time PLM colleague reacted with the following point (full thread here)
Ilan is pointing to the right challenge in many companies. Changing the way you work is though exercise and requires a good understanding, vision, and execution to move forward. Do not trust the tool to work for you – it is about human understanding and process re-engineering to be more efficient. And if you do not practice this on the basic PDM-level as discussed so far, imagine the impossibility of going through a digital transformation.
Last time in the series Learning from the past to understand the future, we zoomed in on how the 3D CAD-structure in the mid-market had to evolve. In a typical Engineering To Order (ETO) scenario, it makes sense to extract from the 3D CAD-structure a BOM-structure to collect all the individual parts that are needed for manufacturing. Combined with the drawings generated based on the 3D CAD assemblies/parts, the complete manufacturing information could be provided. Let’s have a look.
The BOM in ERP (part 1)
To understand what most mid-market companies have been doing, I created the image below. When you click on it, you will have an enlarged version.
Note: for educational purposes an extremely simplified example
There is a lot to explain here.
First, on the right we see the 3D CAD assembly, two phantom assemblies, grouping the wheels and the axle. And at the end, the individual parts, i.e. chassis, axle, and wheel. The 3D CAD-structure is an instance-based structure; therefore, there are no quantities in the structure (all quantity 1)
For the individual parts, there are drawings. Also, for the product, we have an assembly drawing. The drawings are essential as we want to have them in the ERP-system for manufacturing.
Finally, the physical parts, now with a different ID than the drawing as we learned this one-to-one relation created a lot of extra work. The physical parts are often called Items or Materials (SAP naming). Unfortunately, for engineering, there is a different meaning behind Materials. Still, SAP’s data model was not built with an engineering mindset.
The physical part structure, which we call the BOM contains quantities. Most PDM-CAD-integrations can filter out phantom assemblies and summarize the parts on the same level
I am still reluctant to call the Part-structure an EBOM as the design of the product has been mainly focusing on extracting manufacturing information, parts, and drawings.
The BOM in ERP (part 2)
In customized PDM-implementations, some implementers created an interface from the BOM-structure to ERP, so the ERP-system would have the basic definition of the parts and a copy of the relevant drawings.
Now manufacturing could create the manufacturing definition without the need to go into the PDM-system.
Some “clever” – Dick Bourke would say “smart – therefore lazy” – proposed to “draw” also manufacturing entities in the 3D CAD-structure, so the PDM-CAD-interface would automatically deliver manufacturing parts too inside the ERP. In the example below, we added paint for the body and grease needed for the axels.
Although “smart, a new problem was introduced here – the 3D CAD-structure, instance-based, always has quantities 1. The extracted BOM would have rounded numbers when considering design parts. Now the grease comes with an estimate of 0.025 kg, assuming quantities are based on SI-units. We could also add other manufacturing information to this BOM, like 0.3-liter paint. Anyway, the result would look like below:
Important to notice from the diagram here: There are placeholders for grease and paint “drawn” in the 3D CAD-structure – parts without a geometrical definition and, therefore, not having an associated drawing. However, these parts have a material specification, and therefore in the BOM-structure, they appear as Materials.
Next in the BOM-structure, the engineers would enter the expected/required quantity – which is no longer a rounded number.
At this stage, you cannot call the BOM on the left an EBOM. It is a kind of hybrid structure, combining engineering and manufacturing data. A type of BOM we discover a lot in companies that started with a type of ETO-product.
The ETO-product
Many companies that developed specialized machinery have started with a base product, from where they developed the custom solution – their IP. Next, with more and more customers, the original solution was extended by creating either new or changed capabilities.
I worked a lot with companies that moved to the full definition of their products in 3D CAD, creating a correct 3D CAD-structure per customer order. Instead of creating new BOM variants, companies were often tempted/forced to make the configuration inside the 3D CAD-model.
Every time one of the configurations of the part would change, or a new configuration was added, the file has to be revised.
And if the change was at level five of a 3D CAD-structure, many assembly files needed to be updated. The versioning problem illustrates the challenge of managing configurations inside a 3D CAD-file, meanwhile creating complexity for the PDM/PLM-system.
Last week Tech-Clarity published the highlights of their survey: Bringing Custom-Engineered Products to Market with a link to the full report, sponsored by Propel.
As you can imagine, this survey is more about PLM collaboration, breaking down the silos and acting agile. Unfortunately, the report does not expose required methodologies, like modularity and “common sense” engineering practices that we discuss here. Still worthwhile to read as the report addresses precisely the type of companies I am referring too here.
If we look at the methodology of custom-engineered products, let us look at how their “best practice” from the past is blocking the future.
When a new customer request is coming in, sales engineering is looking for the best match of delivered products. Hopefully, 80-90 % remains the same, and engineering has to focus only on the differences.
First, the best-match 3D CAD-structure is copied to a new project. As you can see most 3D CAD-systems provide the functionality to create a derived structure from an original 3D CAD-structure. From there, a traditional ETO-process starts as described at the beginning of this post. We complete the 3D CAD-structure with manufacturing in mind, generate the BOM and drawings, and we can deliver. In the case of purchase parts, the generated BOM often contains already the supplier part number in the 3D CAD-structure as we are focusing on this single delivery.
The disadvantage of this approach that in theory, we have to check if the structure that we reused is really the best so far, otherwise we introduce errors again.
The second disadvantage is that if one supplier part in the structure becomes obsolete and needs to be revised, the company has to go through all the 3D CAD-structures to fix it.
Also, having supplier parts in the 3D CAD-structure makes it more difficult to standardize, as the chosen supplier part matched the criteria for that customer at that time. Will it match the criteria also in other situations?
From ETO to BTO to CTO
Many companies that started with custom-engineered products, the ETO-approach, want to move towards a Configure To Order (CTO) approach – or if not possible at least Build To Order (BTO). More reuse, less risk, instead of creating every time a new solution for the next customer, as discussed before.
This is not a mission impossible; however, often, I have seen that companies do not set the right priorities to move towards a configure to order environment. There are a few changes needed to become a configure to order company (if possible):
- Analyze your solution and define modules and options. Instead of defining a full solution, the target now is to discover a commonality between the various solutions. Based on commonality, define modules and options in such a manner that they can be used in different situations. Crucial for these modules is that there is a standard interface to the rest of the product. Every company needs to master this specific methodology for their products
- Start defining products from a logical structure, defining how products, modules and options are compatible and which combinations are allowed (or preferred). For companies that are not familiar with logical structure, often a configured EBOM is used to define the solutions. Not the optimal way; however, this was the first approach most companies took ten years ago. I will explain the configured EBOM below.
- A product definition and its modules now should start from a real EBOM, not containing manufacturing characteristics. The EBOM should represent the logical manner of how a product is defined. You will notice this type of EBOM might be only 2 – 3 levels deep. At the lowest level, you have the modules that have their own lifecycle and isolated definition.
- You should no longer use supplier part numbers in your EBOMs. As the engineering definition of a module or option should not depend over time from a single supplier. We will discuss in the next post the relation between EBOM parts and the Approved Manufacturer List (AML)
To conclude for today
Changing from ETO to CTO requires modularity and a BOM-driven approach. Starting from a 3D CAD-structure can still be done for the lowest levels – the modules, the options. In a configure to order process, it might not be relevant anymore to create a full 3D-representation of the product.
However, when we look forward, it would be greatly beneficial to have the 3D-representation of every specific solution delivered. This is where concepts as augmented/virtual reality and digital twin come in.
Next time more on the BOM-structures – as we have just touched the upcoming of the EBOM – enough to clarify next week(s).
In my earlier posts, I explored the incompatibility between current PLM practices and future needs for digital PLM. Digital PLM is one of the terms I am using for future concepts. Actually, in a digital enterprise, system borders become vague, it is more about connected platforms and digital services. Current PLM practices can be considered as Coordinated where the future for PLM is aimed at Connected information. See also Coordinated or Connected.
Moving from current PLM practices toward modern ways of working is a transformation for several reasons.
- First, the scope of current PLM implementation is most of the time focusing on engineering. Digital PLM aims to offer product information services along the product lifecycle.
- Second, because the information in current PLM implementations is mainly stored in documents – drawings still being the leading In advanced PLM implementations BOM-structures, the EBOM and MBOM are information structures, again relying on related specification documents, either CAD- or Office files.
So let’s review the transformation challenges related to moving from current PLM to Digital PLM
Current PLM – document management
The first PLM implementations were most of the time advanced cPDM implementations, targeting sharing CAD models and drawings. Deployments started with the engineering department with the aim to centralize product design information. Integrations with mechanical CAD systems had the major priority including engineering change processes. The multidisciplinary collaboration was enabled by introducing the concept of the Engineering Bill of Materials (EBOM). Every discipline, mechanical, electrical and sometimes (embedded) software teams, linked their information to the EBOM. The product release process was driven by the EBOM. If the EBOM is released, the product is fully specified and can be manufactured.
Although people complain implementing PLM is complex, this type of implementation is relatively simple. The only added mental effort you are demanding from the PLM user is to work in a structured way and have a more controlled (rigid) way of working compared to a directory structure approach. For many people, this controlled way of working is already considered a limitation of their freedom. However, companies are not profitable because their employees are all artists working in full freedom. They become successful if they can deliver in some efficient way products with consistent quality. In a competitive, global market there is no room anymore for inefficient ways of working as labor costs are adding to the price.
The way people work in this cPDM environment is coordinated, meaning based on business processes the various stakeholders agree to offer complete sets of information (read: documents) to contribute to the full product definition. If all contributions are consistent depends on the time and effort people spent to verify and validate their consistency. Often this is not done thoroughly and errors are only discovered during manufacturing or later in the field. Costly but accepted as it has always been the case.
Next Step PLM – coordinated document management / item-centric
When the awareness exists that data needs to flow through an organization in a consistent manner, the next step of PLM implementations comes into the picture. Here I would state we are really talking about PLM as the target is to share product data outside the engineering department.
The first logical extension for PLM is moving information from an EBOM view (engineering) toward a Manufacturing Bill of Materials (MBOM) view. The MBOM is aiming to represent the manufacturing definition of the product and becomes a placeholder to link with the ERP system and suppliers directly. Having an integrated EBOM / MBOM process with your ERP system is already a big step forward as it creates an efficient way of working to connect engineering and manufacturing.
As all the information is now related to the EBOM and MBOM, this approach is often called the item-centric approach. The Item (or Part) is the information carrier linked to its specification documents.
Managing the right version of the information in relation to a specific version of the product is called configuration management. And the better you have your configuration management processes in place, the more efficient and with high confidence you can deliver and support your products. Configuration Management is again a typical example where we are talking about a coordinated approach to managing products and documents.
Implementing this type of PLM requires already more complex as it needs different disciplines to agree on a collective process across various (enterprise) systems. ERP integrations are technically not complicated, it is the agreement on a leading process that makes it difficult as the holistic view is often failing.
Next, next step PLM – the Digital Thread
Continuing reading might give you the impression that the next step in PLM evolution is the digital thread. And this can be the case depending on your definition of the digital thread. Oleg Shilovitsky recently published an article: Digital Thread – A new catchy phrase to replace PLM? related to his observations from ConX18 illustrate that there are many viewpoints to this concept. And of course, some vendors promote their perfect fit based on their unique definition. In general, I would classify the idea of Digital Thread in two approaches:
The Digital Thread – coordinated
In the Digital Thread – coordinated approach we are not revolutionizing the way of working in an enterprise. In the coordinated approach, the PLM environment is connected with another overlay, combining data from various disciplines into an environment where the dependencies are traceable. This can be the Aras overlay approach (here explained by Oleg Shilovitsky), the PTC Navigate approach or others, using a new extra layer to connect the various discipline data and create traceability in a more or less non-intrusive way. Similar concepts, but less intrusive can be done through Business Intelligence applications, although they are more read-only than a system approach.
The Digital Thread – connected
In the Digital Thread – connected approach the idea is that information is stored in an extremely granular way and shared among disciplines. Instead of the coordinated way, where every discipline can have its own data sources, here the target is to be data-driven (neutral/standard formats). I described this approach in the various aspects of the model-based enterprise. The challenge of a connected enterprise is the standardized data definition to make it available for all stakeholders.
Working in a connected enterprise is extremely difficult, in particular for people educated in the old-fashioned ways of working. If you have learned to work with shared documents, like Google Docs or Office documents in sharing mode, you will understand the mental change you have to go through. Continuous sharing of the information instead of waiting until you feel your part is complete.
In the software domain, companies are used to working this way and integrating data in a continuous stream. We have to learn to apply these practices also to a complete product lifecycle, where the product consists of hardware and software.
Still, the connect way of working is the vision that digital enterprises should aim for as it dramatically reduces the overhead of information conversion, overhead, and ambiguity. How we will implement in the context of PLM / Product Innovation is a learning process, where we should not be blocked by our echo chamber as Jan Bosch states in his latest post: Don’t Get Stuck In Your Company’s Echo Chamber
Jan Bosch is coming from the software world, promoting the Software-Centric Systems conference SC2 as a conference to open up your mind. I recommend you to take part in upcoming PLM-related events: CIMdata’s PLM roadmap Europe combined with PDT Europe on 24/25th October in Stuttgart, or if you are living in the US there is the upcoming PI PLMx CHICAGO 2018 on Nov 5/6th.
Conclusion
Learning and understanding are crucial and take time. A digital transformation has many aspects to learn – keep in mind the difference between coordinated (relatively easy) and connected (extraordinarily challenging but promising). Unfortunately there is no populist way to become digital.
Note:
If you want to continue learning, please read this post – The True Impact of Industry 4.0 Revealed -and its internal links to reference information from Martijn Dullaart – so relevant.
In my series describing the best practices related to a (PLM) data model, I described the general principles, the need for products and parts, the relation between CAD documents and the EBOM, the topic of classification and now the sensitive relation between EBOM and MBOM.
First some statements to set the scene:
- The EBOM represents the engineering (design) view of a product, structured in a way that it represents the multidisciplinary view of the functional definition of the product. The EBOM combined with its related specification documents, models, drawings, annotations should give a 100 % clear definition of the product.
- The MBOM represents the manufacturing view of a product, structured in a way that represents the way the product is manufactured. This structure is most of the time not the same as the EBOM, due to the manufacturing process and purchasing of parts.
A (very) simplified picture illustrating the difference between an EBOM and a MBOM. If the Car was a diesel there would be also embedded software in both BOMs (currently hidden)
For many years, the ERP systems have claimed ownership of the MBOM for two reasons
- Historically the MBOM was the starting point for production. Where the engineering department often worked with a set of tools, the ERP system was the system where data was connected and used to have a manufacturing plan and real-time execution
- To accommodate a more advanced integration with PDM systems, ERP vendors began to offer an EBOM capability also in their system as PDM systems often worked around the EBOM.
These two approaches made it hard to implement “real” PLM where (BOM) data is flowing through an organization instead of stored in a single system.
By claiming ownership of the BOM by ERP, some problems came up:
- A disconnect between the iterative engineering domain and the execution driven ERP domain. The EBOM is under continuous change (unless you have a simple or the ultimate product) and these changes are all related to upstream information, specifications, requirements, engineering changes and design changes. An ERP system is not intended for handling iterative processes, therefore forcing the user to work in a complex environment or trying to fix the issue through heavy customization on the ERP side.
- Global manufacturing and outsourced manufacturing introduced a new challenge for ERP-centric implementations. This would require all manufacturing sites also the outsourced manufacturers the same capabilities to transfer an EBOM into a local MBOM. And how do you capitalize the IP from your products when information is handled in a dispersed environment?
The solution to this problem is to extend your PDM implementation towards a “real” PLM implementation providing the support for EBOM, MBOM, and potential plant specific MBOM. All in a single system / user-experience designed to manage change and to allow all users to work in a global collaborative way around the product. MBOM information then will then be pushed when needed to the (local) ERP system, managing the execution.
Note 1: Pushing the MBOM to ERP does not mean a one-time big bang. When manufacturing parts are defined and sourced, there will already be a part definition in the ERP system too, as logistical information must come from ERP. The final push to ERP is, therefore, more a release to ERP combined with execution information (when / related to which order).
In this scenario, the MBOM will be already in ERP containing engineering data complemented with manufacturing data. Therefore from the PLM side we talk more about sharing BOM information instead of owning. Certain disciplines have the responsibility for particular properties of the BOM, but no single ownership.
Note 2: The whole concept of EBOM and MBOM makes only sense if you have to deliver repetitive products. For a one-off product, more a project, the engineering process will have the manufacturing already in mind. No need for a transition between EBOM and MBOM, it would only slow down the delivery.
Now let´s look at some EBOM-MBOM specifics
EBOM phantom assemblies
When extracting an EBOM directly from a 3D CAD structure, there might be subassemblies in the EBOM due to a logical grouping of certain items. You do not want to see these phantom assemblies in the MBOM as they only complicate the structuring of the MBOM or lead to phantom activities. In an EBOM-MBOM transition these phantom assemblies should disappear and the underlying end items should be linked to the higher level.
EBOM materials
In the EBOM, there might be materials like a rubber tube with a certain length, a strip with a certain length, etc. These materials cannot be purchased in these exact dimensions. Part of the EBOM to MBOM transition is to translate these EBOM items (specifying the exact material) into purchasable MBOM items combined with a fitting operation.
EBOM end-items (make)
For make end-items, there are usually approved manufacturers defined and it is desirable to have multiple manufacturers (certified through the AML) for make end-items, depending on cost, capacity and where the product needs to be manufactured. Therefore, a make end-item in the EBOM will not appear in a resolved MBOM.
EBOM end-items (buy)
For buy end-items, there is usually a combination of approved manufacturers (AML) combined with approved vendors (AVL). The approved manufacturers are defined by engineering, based on part specifications. Approved vendors are defined by manufacturing combined with purchasing based on the approved manufacturers and logistical or commercial conditions
Are EBOM items and MBOM items different?
There is a debate if EBOM items should/could appear in an MBOM or that EBOM items are only in the EBOM and connected to resolved items in the MBOM. Based on the previous descriptions of the various EBOM items, you can conclude that a resolved MBOM does not contain EBOM items anymore in case of multiple sourcing. Only when you have a single manufacturer for an EBOM item, the EBOM item could appear in the MBOM. Perhaps this is current in your company, but will this stay the same in the future?
It is up to your business process and type of product which direction you choose. Coming back to one-off products, here is does not make sense to have multiple manufacturers. In that case, you will see that the EBOM item behaves at the same time as an MBOM item.
What about part numbering?
Luckily I reached the 1000 words so let´s be short on this debate. In case you want an automated flow of information between PLM and ERP, it is important that shared data is connected through a unique identifier.
Automation does no need intelligent numbering. Therefore giving parts in the PLM system and the ERP system a unique, meaningless number you ensure guaranteed digital connectivity.
If you want to have additional attributes on the PLM or ERP side that describe the part with a number relevant for human identification on the engineering side or later at the manufacturing side (labeling), this all can be solved.
An interesting result of this approach is that a revision of a part is no longer visible on the ERP side (unless you insist). Each version of the MBOM parts is pointing to a unique version of an MBOM part in ERP, providing an error free sharing of data.
Conclusion
Life can be simple if you generalize and if there was no past, no legacy and no ownership of data thinking. The transition of EBOM to MBOM is the crucial point where the real PLM vision is applied. If there is no data sharing on MBOM level, there are two silos, the characteristic of the old linear past.
(See also: From a linear world to a circular and fast)
What do you think? Is more complexity needed?
I will be soon discussing these topics at the PDT2015 in Stockholm on October 13-14. Will you be there ?
And for Dutch/Belgium readers – October 8th in Bunnik:
Op 8 oktober ben ik op het BIM Open 2015 Congres in Bunnik waar ik de overeenkomsten tussen PLM en BIM zal bespreken en wat de constructie industrie kan leren van PLM
In my earlier posts, I described generic PLM data model and practices related to Products, BOMs en recently EBOM and (CAD) Documents. This time I want to elaborate a little bit more on the various EBOM characteristics.
The EBOM is the place where engineering teams collaborate and define the product. A released EBOM is supposed to give the full engineering specification how a product should behave including material quality and tolerances. This makes it different from the MBOM, which contains the specification of how this product should be manufactured based on exact components and materials.
Depending on the type of product there are several EBOM best practices which I will discuss here (briefly) in alphabetical order:
EBOM & Buy Part
Usually, an EBOM consists of Make and Buy parts –an attribute on the EBOM part indicates the preferred approach. Make parts are typically sourced towards qualified suppliers, where Buy parts can be more generic and based on qualified vendors. Engineering specifies who are the approved Manufacturers for the part (AML) and purchasing decides who are the approved Vendors for this part (AVL). In general Buy parts do not need an engineering efforts every time the part is used in a product.
EBOM & CAD related
My previous post already discussed some of the points related to EBOM and CAD Documents. Here I want to extend a little more addressing the close relation between MCAD parts and EBOM parts. In particular in the Engineering To Order industry, there is, most of the time, no standard product to relate to. In that case, Mechanical CAD can be the driver for the EBOM definition and usually EBOM Make parts are designed uniquely. The challenge is to understand similar parts that might exist and reuse them. Classification (and old post here) and geometric search capabilities support the modern engineer. I will come back to classification in a later post
EBOM – Configuration Item
In case a product is designed for mass production throughout a longer lifetime, it becomes necessary to manage the product configuration over time. How is the product is defined today and avoid the need to have for each product variant a complete EBOM to manage. The EBOM can be structured with Options and Variants. In that case, having Configuration Items in the EBOM is crucial. The Configuration Item is the top part that is versioned and controlled. Parts below the configuration item, mostly standard parts do not impact the version of the Configuration Item as long as the Form-Fit-Function from the Configuration Item does not change. Configuration Management is a topic on its own and some people believe PLM systems were invented to support Configuration Management.
EBOM – Company Standard Part
Standard Parts are often designed parts that should be used across various products or product lines. The advantage of company standard parts is that it reduces costs throughout the whole product lifecycle. Less design time, less manufacturing setup time and material sourcing effort and potential lower material cost thanks to higher volumes. Any EBOM part could become at a certain moment a Company Standard part and it is recommended to use a classification related to these parts. Otherwise they will not be found again. As mentioned before I will come back to classification.
EBOM – Functional group
Sometimes during the design of a product, several parts are logically grouped together from the design point of view, either because they are modular or because they always appear as a group of parts.
The EBOM, in that case, can contain phantom parts, which do not represent an end item. These phantom parts assist the company in understanding changing one of the individual parts in this functional group.
EBOM – Long Lead
In typical Engineering to Order or Build To Order deliveries there are components on the critical path of the product delivery. Components with a long lead time should be identified and ordered as early as possible during the delivery process. Often the EBOM is not complete or mature enough to pass through all the information to ERP. Therefore Long Lead items require a fast track towards ERP and a special status in the EBOM reflecting its ordering status. Long Lead items are the example where a company can benefit from a precise interaction between PLM and ERP with various status handshakes and approvals during the delivery process
EBOM – Make parts
Make Parts in an EBOM are usually specified by their related model and drawings. Therefore Make Parts usually have revisions but be aware that they do not follow the same versioning of the related model or drawing. A Make Part is in an In Work status as long as the EBOM is not released. Once the model is approved, the EBOM part can be approved or released. Often companies do not want to release the data as long as manufacturing is not completed. This to make sure that the first revision comes out at the first delivery of the product.
EBOM – Materials
In many mechanical assemblies, the designer specifies materials with a particular length. For example a rubber strip, tubing / piping. When extracting the information from the 3D CAD assembly, this material instance will get a unique identifier. Here it is important that the Material Part has an attribute that describes the material specification. In the ideal data model, this is a reference to a Materials library. Next when manufacturing engineering is defining the MBOM, they can decide on material quantities to purchase for the EBOM Material.
EBOM – Part Number
This could be a post on its own. Do we need intelligent part numbers or can we use random generated unique numbers? I have a black and white opinion about that. If you want to achieve a digital enterprise you should aim for random generated unique numbers. This because in a digital enterprise data is connected without human transfer. The PLM and ERP link is unambiguous. Part recognition at the shop floor can be done with labels and scanning at the workstation. There is no need for a person to remember or transfer information from one system or location by understanding the part number. The uniquely generated number make sure every person will have a look at the digital metadata online available. Therefore immediately seeing a potential status change or upcoming engineering change. Supporting the intelligent numbering approach allows people to work disconnected again, therefore not guaranteeing that an error-free activity takes place. People make mistakes, machines usually not.
EBOM – Service Parts
It is important to identify already in the EBOM which parts need to be serviced in operation and engineering should relate the service information already to the EBOM part. This could be the same single part with a different packaging or it could be a service kit plus instructions linked to the part. In a PLM environment, it is important that this activity is done upfront by engineering to avoid later retrieval of the data and work again on service information. A sensitive point here is that engineers currently in the classical approach are not measured on the benefits they deliver downstream when the products are in the field. Too many companies work here in silos.
EBOM – Standard Parts
Finally, as I reach already the 1000 words, a short statement about EBOM standard parts. These standard parts, based on international or commercial standards do not need a revision and often they have a specification sheet, not necessary a 3D model for visualization. Classification is crucial for Standard Part and here I will write a separate post about dealing with Standard Parts, both mechanical and electrical.
Concluding: this post we can see that the EBOM is having many facets and based on the type of EBOM part different behavior is expected. It made me realize PLM is not that simple as I thought. In general when defining an EBOM data model you would try to minimize the specific classes for the EBOM part. Where possible, solve it with attributes (Make/Buy – Long Lead – Service – etc.). Use classification to store specific attributes per part type related to the part. Classification will be my next topic as it appears
Feel free to jump on any of the EBOM characteristics for an extended discussion
note: images borrowed from the internet contain links to the original location where I found them. The context there is not always relevant for this post.
In my series of blog posts related to the (PLM) data model, I talked about Product, BOMs and Parts. This time I want to focus on the EBOM and (CAD) Documents relation. This topic became relevant with the introduction of 3D CAD.
Before companies were using 3D CAD systems, there was no discussion about EBOM or MBOM (to my knowledge). Engineering was producing drawings for manufacturing and not every company was using the mono-system (for each individual part a specifying drawing). Drawings were mainly made to assist production and making a drawing for an individual part was a waste of engineering time. Parametric drawings were used to specify similar parts. But now we are in the world of 3D!
With the introduction of 3D CAD systems for the mainstream in the nineties (SolidWorks, Solid Edge, Inventor) there came a need for PDM systems managing the individual files from a CAD assembly. The PDM system was necessary to manage all the file versions. Companies that were designing simple products sometimes remained working file-based, introducing the complexity of how to name a file and how to deal with revisions. Ten years ago I was investigating data management for the lower tiers of the automotive supply chain. At that time still 60 % of the suppliers were using CATIA were working file-based. Data management was considered as an extra complexity still file version control was a big pain.
This has changed for several reasons:
- More and more OEMs were pushing for more quality control of the design data (read PDM)
- Products became more modular, which means assemblies can be used as subassemblies in other products, pushing the need for where used control
- Products are becoming more complex and managing only mechanical CAD files is not enough anymore – Electronics & Software – mechatronics – became part of the product
Most PDM systems at that time (I worked with SmarTeam) were saving the 3D CAD structure as a quantity-based document structure, resembling a lot a structure called the EBOM.
This is one of the most common mistakes made in PLM implementations.
The CAD structure does not represent the EBOM !!!
Implementers started to build all kind of customizations to create automatically from the CAD structure a Part structure, the EBOM. Usually these customizations ended up as a mission impossible, in particular when customers started to ask for bidirectional synchronization. They expected that when a Part is removed in the EBOM, it would be deleted in the CAD assembly too.
And then there was the issue that companies believed the CAD Part ID should be equal to the Part ID. This might be possible for a particular type of design parts, but does not function anymore with flexible parts, such as a tube or a spring. When this Part is modeled in a different position, it created a different CAD Document, breaking the one-to-one relation.
Finally another common mistake that I have seen in many PDM implementations is the addition of glue, paint and other manufacturing type of parts to the CAD model, to be able to generate a BOM directly from the CAD.
From the data model perspective it is more important to understand that Parts and CAD documents are different type of objects. In particular if you want to build a PLM implementation where data is shared across all disciplines. For a PDM implementation I care less about the data model as the implementation is often not targeting enterprise continuity of data but only engineering needs.
A CAD Document (Assembly / Part / Drawing / …) behaves like a Document. It can be checked-in and checked out any time a change is made inside the file. A check-in operation would create a new version of the CAD Document (in case you want to trace the history of changes).
Meanwhile the Part specified by the CAD Document does not change in version when the CAD Document is changed. Parts usually do not have versions; they remain in the same revision as long as the specifying CAD Document matures.
Moving from PDM to PLM
For a PLM implementation it is important to think “Part-driven” which means from an initial EBOM, representing the engineering specification of the Product, maturing the EBOM with more and more design specification data. Design specification data can be mechanical assemblies and parts, but also electrical parts. The EBOM from a PCB might come from the Electrical Design Application as in the mechanical model you will not create every component in 3D.
And once the Electrical components are part of the EBOM, also the part definition of embedded software can be added to the BOM. For example if software is needed uploaded in flash memory chips. By adding electrical and software components to the EBOM, the company gets a full overview of the design maturity of ALL disciplines involved.
The diagram below shows how an EBOM and its related Documents could look like:
This data model contains a lot of details:
- As discussed in my previous post – for the outside world (the customer) there is a product defined without revision
- Related to the Product there is an EBOM (Part assembly) simplified as a housing (a mechanical assembly), a connector (a mechanical art) and a PCB (a mechanical representation). All these parts behave like Mechanical Parts; they have a revision and status.
- The PCB has a second representation based on an electrical schema, which has only (for simplification) two electrical parts, a resistor and a memory chip. As you can see these components are standard purchasable parts, they do not have a revision as they are not designed.
- The Electrical Part Flash Memory has a relation to a Software Part which is defined by Object Code (a zip-file?) which of course is specified by a software specification (not in the diagram). The software object code has a version, as most of the time software is version managed, as it does not follow the classical rules of mechanical design.
Again I reached my 1000 words, a sign to stop explaining this topic. For sure there are a lot of details to explain to this data model part too.
Most important:
- A CAD structure is not an EBOM (it can be used to generate a part of the EBOM)
- CAD documents and EBOM parts have a different behavior. CAD documents have versions, Parts do not have versions (most of the time
- The EBOM is the place where all disciplines synchronize their data, providing during the development phase a single view of the design status.
Let me know if this was to abstract and feel free to ask questions. Important for this series of blog post is to provide a methodology baseline for a real PLM data model.
I am looking forward to your questions or remarks to spark up the discussion.
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