Posts Tagged "BOM"

A classic deployment of a digital twin includes three pillars: product design, manufacturing process planning and feedback loops.

  1. Product design

A digital twin includes all design elements of a product, namely:

  • 3D models using computer-aided design (CAD) systems
  • System models (using systems engineering product development solutions, such as systems-driven product development)
  • Bill-of-materials (BOM)
  • 1D, 2D and 3D analysis models using computer-aided engineering (CAE) systems such as Simcenter™ software
  • Digital software design and testing using application lifecycle management (ALM) systems such as Polarion ALM software
  • Electronics design using systems developed by Mentor Graphics

Using these elements results in a comprehensive computerized model of the product, enabling almost 100 percent of virtual validation and testing of the product under design. All of this eliminates the need for prototypes, reduces the amount of time needed for development, improves the quality of the final manufactured product and enables faster iterations in response to customer feedback.

  1. Manufacturing process planning

The Siemens solutions available today enable the development of three models critical to any manufacturer:

  • Manufacturing process model – the how – resulting in an accurate description of how this product will be produced
  • Production facility model – the where – providing a full digital representation of the production and assembly lines needed to make the product
  • Production facility automation model – Describing how the automation system, including supervisory control and data acquisition (SCADA) systems, programmable logic controller (PLC) hardware and software, human-machine interface (HMI) hardware and software, etc., will support the production system

The value of the digital twin in manufacturing offers a unique opportunity to virtually simulate, validate and optimize the entire production system. It also lets you test how the product, with all its primary parts and subassemblies, will be built using manufacturing processes, production lines and automation.

  1. Feedback loops

When it comes to the feedback loops of the Digital Twins pillars , there are two kinds that have a significant impact on most manufacturers

  • The Smart Factory Loop and
  • The Smart Product Loop.

“Product Design” and “Manufacturing process planning” pillars were in existence for  a while but the “Feedback loops” is a newer one. I will discuss elaborately on it in my next blog .

In a world of controlled, strict, non-flexible systems, people start to get creative.  For some, it’s the crushing weight of a massively customized ERP system that somehow spread out to every part of the organization, for others circumventing “inconvenient” safety devices; when things need to get done, sometimes we have to take matters into our own hands.  In the IT world, this is called “Shadow IT,” which is basically any app, software, or program that isn’t under the control (or even known to) the IT department. Users downloading freeware, buying their own software, using cloud services, etc. Even NASA has difficulty reining in their employees when it comes to using non-sanctioned software.

This behavior extends into the design and engineering office as well, perhaps moreso than other parts of an average organization. It’s in their nature to solve problems; it’s kind of the key attribute of an engineering job description! I can understand why – engineers live and breathe efficiency, and being over-encumbered by poorly designed systems is not efficient at all.

Case in point: the Bill of Materials (BOM). How many systems are controlling it? ERP? The design tool? PDM?  Some home-grown custom system?  By and large…no.  Most work-in-process BOMs are done in spreadsheets.  And why not?  Spreadsheet applications are easy to use and share, don’t require much training, and don’t require six levels of approval to implement. Spreadsheets can even be automated with macros, making BOMs configurable and intelligent. Eventually all items do end up in the ERP, though typically not until late in a product’s/project’s/program’s lifecycle.

So, why not stay with the spreadsheets? What if someone edits those macros and an unknowing user doesn’t verify the end result? What if the file gets corrupted? How does the rest of the organization gain visibility to the latest changes? What ensures that the BOM is up to date with the design? Ultimately, the BOM should be controlled in a PLM system, much to chagrin of clever engineers everywhere.  Here’s why.

Just as when the market moved from pencil drawings, french curves, vellums, and other manual drafting techniques to 2D CAD tools, and similarly 2D design to 3D modeling: Change.  Yes, sketching a part is faster than creating the lines and circles – but CAD technology enables updates caused by change much faster than a manual process. The gains of going from 2D designs to 3D models are more staggering.  “You mean one edit and it updates everywhere?  Even the drawing?”  Anecdotally, I had a customer say “With 2D, whenever the shop called, I was worried about what we messed up.  Now, with 3D models, when the shop calls, I worry about what they messed up.

Again, it’s about rate of change, propagation and validation of the change. Spreadsheets cannot do that (unless you have some really wicked cool macros).

With our PLM Analytics Benchmark, we can help your company to assess the nature of your BOM needs, as well as the 16 pillars of PLM. Let us know if we can be of service!

item-documentationLet’s review the role of the Item Master in managing components and all of the relevant documentation in Autodesk Vault.  There are three main uses for the Item Master in Vault:

  1. Container for all relevant documentation – Items as a concept in Vault are really nothing more than a container for all the relevant documentation related to a component. This could be a PDF file, AutoCAD drawing, or Inventor part and drawing.  This is most commonly done by promoting a document to an Item, where it is assigned an item number.  If an Inventor part or assembly is promoted, the associated drawing is also captured, and this begins the process of capturing all the relevant documentation.
  2. Mechanism for release management – Like individual files, Items also have their own workflows and release process. So rather than trying to manage the release of each individual file, the entire package of relevant documentation can be released from the item level instead.
  3. item-bomCommon BOM format for communication to other business systems – Items also allow the management of a Bill of Materials (BOM). A BOM can be built from scratch from multiple items; however, this is more commonly automated from Autodesk Inventor file relationships.  An Inventor top-level assembly will automatically generate the beginning of a BOM in the Item Master.  This BOM can then be edited to add extra items or change quantities if desired. This BOM can also be exported to a neutral format for communication to other business systems such as ERP or MRP.

A Bill of Material (BOM) at its core is a very simple concept: a list of components needed to manufacture a finished product. So if one was making a pair of spectacles, the BOM may look as follows:

Finished Product Spectacles Quantity
Item 1 Right Lens 1
Item 2 Left Lens 1
Item 3 Frame 1
Item 4 Hinge 2

It must be said that understanding how a BOM functions is fundamental to understanding how PLM systems work. This simple list is really at the core of the PLM system. However, simple concepts have a tendency to escalate into very complex subjects. And so it is with a BOM.

One of the complexities associated with a BOM is that an organization usually has a requirement for different types of a BOM in order to define a single product. Most manufacturing companies have at least three types:

  1. EBOM (Engineering BOM) is the list of parts that engineers are responsible for and comprises all the components that require some sort of design input.
  2. MBOM (Manufacturing BOM) is the list of parts that are required to actually make the product. This is typically different from EBOM by components that engineering do not specifically design (glue strips, liquid fills etc.). It may also be plant specific.
  3. XBOM (Service BOM) is an as built list of parts used in a product that actually made it off the factory floor. This may be different from what was originally specified by the MBOM because of crisis during manufacture. It is important from a customer service perspective.

So the question is: how are your three BOMs authored, edited, maintained, and released? Whatever the answer to this question, the outcome is always the same:

  1. No BOM – No product
  2. Wrong BOM – Factory rework or customer dissatisfaction.

An informal survey of small to medium size companies yields surprising results: Excel is the predominant BOM management tool in an engineering environment. Manufacturing BOMs are normally handled by some sort of ERP system and service BOMs are poorly tracked, if at all. This situation is fraught with potential for disaster because of all the manual processes that have to occur before an actual product gets made.

Hence the analogy in the title. BOM management may be a hidden problem that is set to explode in an organization, especially as the products being made become more complex. PLM systems can offer a single organized BOM that represents all the different types in a consistent, controlled manner. Given the potential consequences of the bomb exploding, BOM in PLM should be a priority.

Do you have a BOM management disaster of your own to share? How about a BOM management triumph?

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