Master Model Rules

[hygear]

I am putting together a proposal to improve the way in which my company creates Pro/E master models for large project. At the moment, we are using the wild west approach and it has caused some serious issues with both drawing/model consistency and prototype parts. To help clean things up, I am trying to put together a list of fundamental rules that must be followed to make sure we keep things from getting out of hand again. Here is what I have so far:

1. At the beginning of each project, a master model architect is assigned to maintain the master model and verify that it meets the remaining rules throughout the project.
2. Every master model should begin with a true skeleton model with basic layout information.
3. There should be no models created outside of the master model. For example, do not create a model for the sole purpose of making a drawing view.
4. The master model should be structured exactly the same as the manufacturing/engineering BOM.
5. Extra assembly/subassembly levels that do not exist in the BOM are strictly forbidden.
6. Part quantity in the model should match the manufacturing/engineering BOM. Flexible components, mechanism, and family tables should be utilized to make this possible. Placing the same component multiple times to show range of motion is forbidden.
7. Assembly models should be created using the master model coordinate system. This means that when the assembly is placed in the master model using the “DEFAULT” constraint, it should assemble to the correct location.
8. Drawings should be created using only the part/assembly model of interest. If a background view is needed to clarify how a part or assembly is used, the master model should be utilized to make the background view and the part/assembly view should be aligned over top of the background view.
9. When a background view is created using the master model, a Simplified Rep should be created in the master model and named according to the drawing in which it was used.
10. Before building prototypes, a design freeze is required and a prototype master model snapshot must be created. This is done by renaming the working copy of the master model (including all parts, but excluding standard parts) with a suffix designating the prototype build number. For example, first prototype parts would get a P1 suffix. After renaming is complete, the prototype master model should be set Read Only. The working copy of the master model will not have suffix and is the only copy that should be modified at any time during the design process. Note: This step was added because there are no clean breaks between prototypes in the current process. This has caused many issues in which the designer is working on a new design but referencing old prototype parts without knowing.

If anyone has additional rules or arguments against my current list of rules, I would love to hear them.

 

[qnen]

My only comment with be with rule 5. We often make small subassemblies to simplify things. Most times the subassembly has the same name as the main assembly with a "--n" (n being consecutive intergers). In our drawing BOM format, we have a filter rule that hides any item with a "--" in its name. The other technique we use is to make the subassembly its own unique number and include it in the BOM. (the parts in the subassembly are not included in that level BOM, rather a drawing of the subassembly must be made and tracked as an entity)

We are trying to get to the point that our CAD system drives our MRP system. Right now, we have some things where the MRP system is the master and the CAD is a disjointed mess of double listed items or items not shown at all or ......

Hope you have luck with your endeavor.


Michael Kuehnen, Kansas City

 

[loki3000]

what kind of models are you designing so that you can have a master model for them? usually i didn't find the need for such a variable design (e.g. change the skeleton - change the model).
it was either design table/ different parts for standardised equipment or just a one-of-a-kind model (more often then the former).

 

[hygear]

@loki3000,my company designs agricultural equipment and each machine is different. Even machines in the same class can be very different in design/construction, and things are constantly evolving. Also, my company is terrible at "Kaizen" or making continual improvements to existing designs. Because of this, we do a ground-up redesign with each new model which requires a whole new master model.