Concurrent Engineering - Share your experiences!

Bettina,

Wow! I find that T/F question amazing. (I guess the presumed need for PDM systems has successfully invaded the mindset.) Top Down design was here (in Pro) long before sophisticated PDM. The two may have synergy, but they are independent. Top Down design is wonderful, powerful methodolgy even if you have a one-user, one-seat enterprise. To my mind, the answer is TRUE without question.

David

Hi

Can someone tell me what exactly do they mean by "top down design" Noone ever told me properly. It is possible I work that way (like they showed me) without knowing. I do not use an PDM system.

Regards

Chris

Hello All,

Talking about these great terms like Top-Down Design and Concurrent Engineering may sound very nice, but it seems like some people are messing them up a little bit .

Top-Down Design

Top-Down Design means "Structure First" - meaning you start by designing the overal structure of an assembly, without bothering yet about detailing the different components. In Pro/ENGINEER this is typically done by creating a high-level skeleton, filling the assembly structure with necessary components (can be parts or subassemblies) to be designed, and sharing geometry from that high-level skeleton to underlying subassembly skeletons and parts. Would you need a PDM system for that ? Well, you could do without for sure - but what about managing dependencies between objects, revision control or the simple advantage of being able to search a database for your cad documents ? A PDM System will always be a good help.

Concurrent Engineering

But what about Concurrent Engineering ? What does this mean ? Well for me it means that you work on one and the same design with different people at the same time. Of course not modeling one and the same model at one moment, but working on different pieces of a large assembly. One engineer may be working on the top-level assembly and skeleton, while some others may be working on some subassemblies. This can be combined with top-down design - both design practices are very complementary. But this is not an obligation. What you definitely need for Concurrent Engineering however is a PDM System. Without PDM, trying concurrent engineering could turn into a nightmare because you just wouldn't see who's working on what data. Personally I have very good experience with Windchill PDMLink at my customer projects as Pro/ENGINEER Application Consultant. PDMLink is a great help. At all times your workspace views show you what objects are being checked out and modified by someone else, what data you are currently modifiying, and so on. Updating the data in your workspace with changes in the commonspace by your collegues is just a piece of cake !

'Update and Integrate'

One particular Pro/ENGINEER workgroup manager function that is really amazing is the "Update and Integrate" functionality. (Available since wildifire 4)

I would like to explain this a little bit more in detail because it is really concurrent engineering driven to the top !

This function will even allow to "merge" changes from different people to the same model. Now one could throw up that with a PDM system only one user could checkout a model (aka a server lock) to make changes to it. Well indeed - that just what the checkout function does - only one user can checkout the object and thus has the right to check in a new iteration of it to the commonspace. Let's say person A has checked out subassembly_1 for making changes to it (adding a new component to it). At the same time person B, who is working on subassembly_2 but also has te subassemby_1 in his workspace (because his working with an external simplified representation of the top-level assembly e.g.). Now person B would also like to make a change to subassembly_1. He would like to move one of the components in subassembly_1 to make some space for a component in his subassembly_2 to avoid interference. Now when trying to make that change, person B will be presented a dialog asking him to either checkout the subassembly_1 or continue without checkout. At that time, a checkout is not possible, because it is still checked out by person A. PDMLink would indicate this in the Event Manager or in the workspace view or you could see it in the 'Database status column' that can be added to the model tree. So the only option for person B at that time is to 'continue' and modify the subassembly_1 and save his changes in his local workspace. As long as the subassembly_1 is checked out by person A, there is no chance that person B can check in his changes to the commonspace. But then comes the time that person A has finished his changes and checks in a new iteration of subassembly_1 to the commonspace. Person B would soon notice this in the 'out-of-date' column in his workspace table view. But what does he do ? He has a locally modified subassembly in his workspace that he cannot checkout because it is not the latest iteration. With an update, he could do two things. In both ways, the metadata will be updated with that on the server. But how should the content be updated ? The update functionality gives him to options for this: either download the content of the latest iteration on the server or re-use the modified content in his local workspace. In the first case, subassembly_1 would have the changes made by person A because that was the latest iteration checked in, but his own modifications would be lost because they object in his workspace is overridden with that on the server. In the second case, he could keep his own modifications, but if he would consequently checkout and check in subassembly_1 a new iteration on the server would be created containing only the changes of person B and thus the changes of person A created in the previous iteration would be lost. That is where the "Update and Integrate" functionality becomes very interesting. It can be accessed from the Pro/ENGINEER file menu, and by activating it, you get a very nice "Comparison" report listing the changes in both the locally modified version, and the newer iteration on the server. At that time, changes could be merged into the model in session (unless they conflict - 2 different changes to the same dimension e.g.) or one could explicitely choose what changes to keep and what changes not to keep from either version. So person B could decide to keep the changes made by person A (adding a component to the subassembly) and his own changes (moving another component in the subassembly) and save the model again in his workspace. Consequently, he could checkout the subassembly since it is updated in the workspace with the latest iteration, and check it in with his changes, while also keeping the changes of person A. Isn't that really "Concurrent Engineering" ? 😉

Many people may say these are 'dangerous' practices, and that it is 'not done' - but I think in many scenarios this is fantastic PDM functionality ! If person B has the rights to checkout the object that was previously checked in by person A, even when not making local changes without checkout, person B could modify the model and (accidentily or not) delete the changes of person A. Finally, with a good workflow defined, his changes would still have to be 'approved' for his new version to get a status 'Released' in the database.

Anyway - I hope it is useful that I can share this experience. Please feel free to add any comment - I would like to learn from other people's experience as well. And to finish, I can tell anyone that Windchill PDMLink is a great PDM tool that really helps you to easily manage your CAD data. Hope I can contribute some more of this stuff in the future if personal time permits...

Greetings,

Tom

As i say on linkedin, i have been using top down design in my projects and at this time i don´t have experience with PDM systems, and this metology works very good alone. But sure when i combine with PDM system this will be most usefull and effective.

I believe 'concurrent engineering' does not imply two people working on the same part with both needing to make a revision to this part. What concurrent engineering means in this respect is engineering from different disciplines working on the same product.

Given the need for mechanical engineers to design the physical part, electrical engineers to design the PC boards, and harness engineers to create the logical and power links.

That is concurrent engineering: different disciplines in engineering working together.

Working at a location with more than 50 engineers in these three disciplines I can tell you the updates Creo Elements has presented are wonderful for the concurrent engineering presented. Sure that there will always be minor points to fix, the overall picture of the operation with regards to the different disciplines involved is a wonderful addition. On a small scale, think of a mechanical engineer designing a bracket but not realizing a wire has to go under the bracket to power a light board in front of it. This just requires a revision of the bracket to accommodate the need of a wire, but what if the engineer could see the wire in the assembly before he made the bracket? With just that knowledge he would account for the wire in the design, and no revision would need to be made.

Now look at this on a larger scale: if the engineers involved in a design could see the wires needed and account for the space needed (one might say that's mechanical also as it has volume), they would add this in to the design and not require additional revisions for this