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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

  1. 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?

  1. 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

  1. 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.
  2. 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.
  3. 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.

The 3D CAD vendor often provided functionality to have multiple configurations of the same part/product inside a single file. A nice feature for designers as there are fewer files to maintain, however, a crime for data management.

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):

  1. 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
  2. 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.
  3. 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.
  4. 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).

The digital thread according to GE

In my earlier posts, I have 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 aiming at Connected information. See also Coordinated or Connected.

Moving from current PLM practices towards modern ways of working is a transformation for several reasons.

  • First, because 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. Multidisciplinary collaboration 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 as 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 its 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 is a consistent manner, the next step of PLM implementations come 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) towards 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 extreme granular way and shared among disciplines. Instead of the coordinated way, where every discipline can have their 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 the information instead of waiting until you feel your part is complete.

In the software domain, companies are used to work this way and to integrate 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 if working is the vision where 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 it 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 takes time. A digital transformation has many aspects to learn – keep in mind the difference between coordinated (relatively easy) and connected (extraordinarily challenging but promising). Unfortunate 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.

clip_image002

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

  1. 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
    clip_image004
  2. 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.
    clip_image006
  • 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?
    clip_image008

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.
clip_image010

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

PhantomWhen 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?

MBOM-MOBMThere 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?

clip_image011Luckily 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?

 

pdt2015

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:

BIMopen2015

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

dummies_logo

 

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

PDM_ERP_AML_AVLUsually, 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

cmiiIn 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

QRThis 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

3dFinally, 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!

imageWith 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.

CAD DOC structure

 

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.

imageFrom 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:

EBOM.docs

 

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.

observation In my previous post, BOM for Dummies related to Configure To Order, I promised to come back on the special relation between the items in the BOM and the CAD data. I noticed from several posts in PLM and PDM groups that also the importance of CAD data is perceived in a different manner, depending on the background of the people or the systems they are experienced with.

So I would like to start with some general statements based on these observations.

planning People who are talking about the importance of CAD data and product structures are usually coming from a background in PDM. In an environment where products are designed, the focus is around data creation, mostly CAD data. The language around parts in the BOM is mostly targeting design parts. So in a PDM environment CAD data is an important topic – therefore PDM people and companies will talk about CAD data and vaults as the center of information.

erp_bom

When you are working in a PLM environment, you need a way to communicate around a product, through its whole lifecycle, not only the design phase but also supporting manufacturing phases, the possible changes of an existing product through engineering changes, the traceability of as-built data and more. In a PLM environment, people have the physical part (often called the ERP part) in mind, when they talk about a part number.

As PLM covers product information across various departments and disciplines, the information carrier for product information cannot be the CAD data. The BOM, usually the mBOM, is the main structure used to represent and produce the product. Most parts in the mBOM have a relation to a CAD document (in many companies still the 2D drawing). Therefore PLM people and companies understanding PLM will talk about items and products and their lifecycle as their center of information.

CAD data in relation to Engineering to Order

The above generalizations have to be combined with the different main business processes. In a strict Engineering To Order environment, where you design and build a solution only once for a specific customer, there is no big benefit of going through an eBOM and mBOM transition.

During the design process the engineer already has manufacturing in mind, which will be reflected in the CAD structure they build – sometime hybrid representing both engineering and manufacturing items. In such an environment CAD data is leading to build a BOM structure.

And in cases where engineering is done in one single 3D CAD system, the company might use the PDM system from this vendor to manage their Bill of Materials. The advantage of this approach is that PDM is smoothly integrated with the design environment. However it restricts in a certain matter the future as we will see in further reading.

pointNot everyone needs the Engineering to Order process !

Moving to an integrated, multi-disciplinary engineering process or changing the main process from Engineering To Order to Built To Order / Configure To Order will cause major challenges in the company.

I have seen in the recent past, several companies that would like to change their way of working from a CAD centric Engineering To Order process towards a more Built to Order or Configure To Order process. The bottle neck of making this switch was every time that engineering people think in CAD structures and all knowledge is embedded in the CAD data. They now want to configure their products in the CAD system.

For Configure to Order you have to look at a different way to your CAD data:

Questions to ask yourself as a company are:

  • When I configure my products around a CAD structure, what should I do with data from other disciplines (Electrical/Tooling/Supplier data) ?
  • When I upgrade my 3D CAD system to a new version, do I need to convert all old CAD data to the newest versions in order to keep my configurations alive?
  • When configuring a new customer solution, do I need to build my whole product in CAD in order to assure it is complete?
  • In Configure to Order the engineering BOM and manufacturing BOM are different. Does this mean that when I go through a new customer order, all CAD data need to be handled, going through eBOM and mBOM transition again?

For me it is obvious that only in an Engineering to Order environment the CAD data are leading for order fulfillment. In all other typical processes, BTO (Built to Order), CTO (Configure to Order) and MTS (Make to Stock),  product configuration and definition is done around items and the CAD data is important associated data for the product definition and manufacturing

In the case of order fulfillment in a Configure to Order process, the CAD structure is not touched as configuration of the product is available based on items. Each item in the mBOM has it relations to CAD data or other specifying information.

In the case of Built To Order, a huge part of the product is already configured, like in Configure To Order. Only new interfaces or functionality will go through a CAD design process. This new design might be released through a process with an eBOM to mBOM transition. In cases where the impact or the amount of data created in engineering is not huge, it is even possible to configure the changes immediately in an mBOM environment.

old_process A second point, which is also under a lot of discussion in the field ( PLM interest groups), is that PDM is easily to introduce as a departmental solution. The engineering BOM is forwarded to manufacturing and there further (disconnected) processed.  The step from PDM to PLM is always a business change.

When PDM vendors talk about ERP integration, they often mean the technical solution of connecting the two systems, not integrating the processes around the BOM (eBOM/mBOM transition) 0r an integrated engineering change (ECR/ECO). See how easy it is according to some PDM vendors:

or
PLM requires an adaptation of all departments to work different and together around a single product definition. Especially in a mid-market company, this is a big issue, as all product knowledge is stored in the CAD data and the knowledge how to produce the product is stored in the mBOM on the ERP side. These environments are often disconnected.
Conclusion: In the context of PDM the importance of CAD data is clear and for companies following a strict Engineering To Order process the main source of product knowledge. Companies following the Built To Order / Configure To Order process should configure their products around items to keep flexibility towards the future.

Companies with the intention to move to Built To Order or Configure To Order should not invest too much in CAD data configuration as it creates a roadblock for the future.

In my next post I will address the question that comes up from many directions, addressed by Jim Brown and others, as discussed  in one of his recent posts around a PLM standard definition and more ….

sleep This is the third post on Bill of Material handling for different types of companies, this time the focus on Configure To Order (CTO). In the CTO process, products are assembled and configured based on customer requirements. This means there is no more engineering needed when customer requirements are known. CTO examples are, the ordering process of a car with all its options, or ordering a personal computer over the internet.

So what has Configure To Order to do with PLM as there is no engineering?

The main PLM activity takes places when designing the configurable product. Designing a product that is configurable, requires a complete different approach as compared to Engineering to Order or Build to Order. Although we see a similar Configure to Order activity in the R&D departments of companies that follow the Build to Order process. They are also designing products or modules that can be used as-is in customer specific orders as part of the solution.

dashboard The challenge of CTO is to design products that are modular, and where options and variants are designed on a common platform with common interfaces. If you look to the dashboard of a car you will see placeholders for additional options (in case you have the minimal car version) and also you might see that for example the radio display in a basic car version differs from the complete board computer in the luxury version. The common platform is one dashboard, fitting to numerous options.

An engineering department will not focus on designing and defining each of the possible combinations of options as this would be impossible to manage. What can be managed is the common platform (the baseline) and all different options on top of this baseline.

So what happens with the BOM?

The initial design of configurable products goes through similar steps as the BTO process, which means starting from a conceptual BOM, moving to an Engineering BOM (eBOM) and finally produce a BOM for manufacturing (mBOM). The difference is that in the CTO process the mBOM is not developed for just one product, but contains all definitions for all possible products. In this situation we talk about a generic mBOM.

Only when a customer order exists, the generic mBOM is resolved into a specific mBOM for this customer order, which then can be sent to the ERP system for execution.

filter In a generic BOM the relations are managed by filters. These filters define the effectivity of the link, in simple words if the relation between two parts in the BOM is valid (and shown) or not. There are various ways to define effectivity – with again a differentiation in usage

  • revision based effectivity – which means the relation between two items is valid in case the revisions match
  • date effectivity – which means the relation is valid during a certain time interval

Both methods are used most of the time for non-configurable products. The revision and date effectivity are used to be able to track the product history through time and therefore to have full traceability. But this does not work if you want to configure every time a customer specific order.

In that case we use unit or option based filtering.

  • unit effectivity – which means the relation between two items is valid for a unit (or a range of units) produced. For example a batch of products or a unique product with a serial number
  • option effectivity – which means the relation between two items is valid in case a certain condition is valid. Which condition depends on the configuration rules for this option. Example of options are: color, version, country

It is clear that unit and option based filtering of a BOM can lead to a conceptual complex product definition which goes beyond the BOM for Dummies target.  Below an illustration of the various filter concepts (oops the animated gif does not work – i will investigate):

CTO

The benefit of this filtering approach is that there is a minimum of redundancy of data to manage. This makes it a common practice in the aerospace and automotive industry. An example describing all the complexity can be found for example here, but I am sure on this level there are enough publications and studies available.

And what about the CAD ?

I will write a separate post on this topic, as all the possible interactions and use cases with CAD are a topic on its own. You can imagine, having the 3D virtual world combined with a configurable BOM brings a lot of benefits

What PLM functions are required to support Configure to Order ?

  • Project management – not so much focus here as the delivery project for a customer does not require much customer interaction. Of course, the product development processes requires advanced capabilities which I will address later in a future post.
  • Document management – same approach as for project management. The product related documentation needs to exist and secured. Customer specific documentation can be generated often automatically.
  • Product Management – managing all released and available components for a solution, related to their Bill of Materials. Often part of product management is the classification of product families and its related modules
  • Item management – The main activities here are in the mBOM area. Capabilities for BOM generation (eBOM/mBOM), baseline and compare using filtering (unit based / option based) in order to support the definition if the manufactured product
  • Workflow processes – As we are dealing with standardized components in the BOM, the Engineering Change Request (ECR) and Engineering Change Order (ECO) processes will be the core for changes. And as we want to manage controlled manufacturing definition, the Manufacturer Change Order process and Standard Item Approval process are often implemented

Optional:

  • Requirements Management – specially for complex products, tracking of individual requirements and their implementation, can save time and costs during delivery to understand and handle the complex platform
  • Service Management – as an extension of item management. When a customer specific order has been delivered it might be still interesting for the company that delivered the product to keep traceability of the customer configuration for service options – managing the Service and As-Built BOM
  • Product Configurator – the reason I write it as optional, is because the target is order execution, which is not a PLM role anymore. The ERP system should be able to resolve the full mBOM for an order. The PLM product configuration definition is done through Product and Item management. Depending on the customer environment the role of configurator might be found in PLM in case ERP does not have the adequate tools.

Conclusion:

It is hard to describe the Configure To Order process in the scope of BOM for Dummies. As various detailed concepts exist per industry there is no generic standard. This is often the area where the PLM system, the PLM users and implementers are challenged the most: to make it workable, understandable and maintainable

Next time some industry specific observations for a change

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