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):


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


  • 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.


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