Revision Rules in Teamcenter

I know engineer’s, they love to change things!

In this blog, we will discuss Teamcenter revision rules

  • Technical: What is a revision?
  • Status: Working, Released, or…?
  • Processes: Applying a status
  • Precise or Imprecise assemblies: What’s the difference?
  • Revision Rules: Opening an assembly for a specific outcome
  • Configurable BOM: What’s a Variant Condition?  (a preview of a future blog)

What is a revision?

When asked…“Is this a new part number, or is this a revision?”, what is your answer?

Of course, your response may be another question, does it change “Form, Fit or Function?”

And then the “animated” discussions start……

The answer is determined by inventory management, not Product Data/Lifecycle Management (PDM/PLM) .

All PDM/PLM systems uniquely identify parts and assemblies, and then manage the CAD models, documents and the specifications that describe them.

As designs mature the part numbers are revised with the most recent learnings.  Parts are then updated or recreated.

The practice of revisioning is described in many documents.

  • DOD-STD-100:
    • The term revision refers to any change after a drawing has been released for use
  • Configuration Management Handbook [Samarus]:
    • Revision letter, a letter added to a drawing or other document number to indicate that a change was made to the original document.
    • Part number, a number used to uniquely identify a part or item.
  • Manufacturing Data Structures [Clement]:
    • Revision level – A number or letter representing the number of times a part drawing or specification has been changed.

Our PDM/PLM systems manages the files we create, the originator however, guides the design to manufacturing process.  Revising and then recording changes is good design practice

As the originator iterates the design, part interchangeability [does the iteration alter form, fit or function] guides the decision process.

Simply stated, if a revised part can be intermingled with previous iterations of that part without any negative effect, then the part iterations are interchangeable, and are revisions

The part number remains unchanged, the revision documentation serves as a record of what changed.

Applying Status: Working, Released, Obsolete, or…?

Product development processes are both time and event based.

In other words, one first creates a part then, over time, matures the idea until is in production.  And when in production, there may be further refinements although at less frequent intervals.

Teamcenter assists us in managing our parts, assemblies, documents, and other details of product development along this timeline, the need to manage access to the files we create surfaces

For example, if you signed a contract to purchase an item, the details of the transaction would be described and your approval states you agreed with these conditions

You wouldn’t want the contract to be changed, without your approval, would you?

Applying status in Teamcenter is analogous to the timeline of a contract approved process

We begin in a Working status mode…

  • No status shows on our item revision, as we are “working on it…”
  • As we are working on a part design, we may refine “Who” is Working at a given time with the concept of owning user.
    • In our contact to purchase analogy, the document has an originator.
      • The document may pass to a reviewer, and then to you
      • As the contract progresses, who can write/modify changes
      • Once an agreement is reached, permission to write transfers

 

Status, in Teamcenter, typically manages when the electronic file is no longer editable, and becomes read-only

  • Such a state would exist after an approval process

Workflow Processes:

Teamcenter applies status through workflows.

  • Status may have many synonymous names….Approved, Reviewed, Released
  • Status may also be informative, such as Ordered or Received

Precise or Imprecise assemblies: What’s the difference?

When configuring an assembly, Teamcenter has many options

The challenge, BOM management terminology can be quite confusing in an engineering context, and yet well understood by planners and forecasters.

Let’s illustrate, with some comparisons

  • Precise Assembly = Static [A specific combination of parts at specific maturity levels]
  • ImPrecise Assembly = Dynamic [An always updating combination of parts at various maturity levels]

An example of a Precise Assembly is put together furniture

  • What is in the box is precisely what is to be assembled
    • How many fasteners, and of which type
    • Individual parts
    • Assembly tools

 

Components are released

Top Level assembly is released

  • Cannot add/subtract components from the assembly

An ImPrecise assembly dynamically updates

 

May be a mix of working on it parts, Released parts, parts in change process.

 

Top Level assembly is NOT released

 

Components may be added/removed as design matures

Revision Rules: Opening an assembly for a specific outcome

In an organization that works from new ideas to sustained production, context is important when opening an assembly

For example:

  • Are you opening an assembly that is early in the concept phase?
  • Are you opening a product to a specific configuration?
  • Does the assembly have a baseline configuration, with selectable options?
  • And so on…

With an objective in mind, opening our assembly requires selecting the revision rule that meets our needs

Analogous to setting switches on/off, the list below illustrates a selected revision rule with its associated details

For example, Any Status; Working would open an assembly that has a mix of in-process and released parts

Latest Working would open a Precise assembly, parts with status (e.g. Released or Approved) and what parts are being updated (Working)

Configurable BOM’s: What’s a Variant Condition?  (a preview of a future blog)

A specific variation of a product can be defined using structured subassemblies

Teamcenter utilizes Variant Conditions for this situation

  • A “150% BOM” is another name for a variant structure, or more precisely, a configurable BOM.
  • Configurable BOM’s include all components of every variation into one product structure.
    • The BOM contains more parts and subassemblies than needed
      • Therefore, the term 150% BOM.
    • If you’ve ever ordered a car or a laptop to a specific arrangement, you have used a configurable BOM.

Examples: 

This chair is the same assembly build, but with several fabrics and height options.

This motorcycle engine has alternate gaskets, fasteners, and a range of shims for valve adjustments

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Post by Craig Robillard

Hello, I'm Craig! With beginnings starting as an engineer/draftsman back in 1983, I was the first user of McAuto Unigraphics II Version 1.0. At that time, Teamcenter was not invented, however the need for file management was soon recognized. I am now an Application Engineer at Swoosh Technologies that specializes in Teamcenter, and has a background in new product development, working on a wide range of products such as the following: Copiers, Ink Jet Printers, Scanners, Satellites like Google Earth, Fusion Energy Research, and Industrial Compressor Design (HVAC).

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