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3D MCAD - CAE - CAM Engineering/Manufacturing Defined
Never the Twain Shall Meet!

This is a description of the purpose of these two functions as it pertains to the implementation of 3D MCAD/CAE/CAM.

Definitions

3D MCAD

We have for years called anything to do with computer aided design – CAD. But in the case of AutoCAD it was Computer Aided Drawing. So, we started with a word that did not describe what we were doing.

How many times have you been in a chat room discussing CAD and found out you were talking to a fellow that was doing “2D” and you were talking about “3D” or visa versa. You just sighed. So today we are discussing 3D MCAD
M (Mechanical) CAD (Computer Aided Design), now we can even get in a little trouble here, as it may relate to HVAC. But we will assume that MCAD refers to the Industrial/Mechanical Industry

CAE – Computer Aided Engineering. This includes and type of engineering analysis or simulation utilizing a computer.

CAM – Computer Aided Manufacturing. This encompasses all of the use of computers in the manufacturing of parts and assemblies including inspection.

We will start with engineering.

I am writing this for the PLM and MBE people that have never done any engineering and are now designing systems that engineering is using.

It the beginning, Engineering drove CAD. 3D CAD was implemented to increase the productivity of making drawings. The purpose of 3D Computervision, Catia and Pro/e was to create drawings from 3D design. In the early 1990's with the introduction of CNC we started delivering the 3D model with the paper prints. It wasn't until the late 1990’s with the release of PDF were we able to email the model and documentation.

You would create the AID (Associated Information Document) we did not draw anymore we 3D modeled. The benefit of course was that if we changed the model all of the AID views would change. Clever, huh?

Engineering’s only purpose is the delivery of concise,
complete and unambiguous documentation to manufacturing.

3D MCAD was doing just that until the late 1990’s. But PLM was introduced at the turn of the century when the high end MCAD systems moved to the PC. I am not sure that they looked and decided on MBE and the single file of the PMI due to the delivering of the paper prints but something drove them to this non-functional process.

This is a PMI
(Product Manufacturing Information)

Why MBE/MBD/PMI Will FAIL

PMI vs AID

 

 


This is an AID
(Associated Information Document)

The Death of the Drawing

The Death of the Draftsman

Both are of the same part.
Which is more clear to you?

But you must remember the AID travels with the 3D model. So the supplier has the 3D model available the same as with the PMI. The AID as referenced in the name is not a stand alone document.

All the mid-ranged users were familiar with the PDF and started utilizing it instantly. Most of the mid-ranged CAD systems incorporated it and allowed you to print a PDF with multiple sheets directly from the program. There are free programs that can print a PDF they act just like a printer. Of course, all of the mid-range allow you to print incredible 3D PDF and many include the PMI such as ZW3D.

The high-end programs took forever to implement many of these very useful features. IGES and STEP were the only import or export formats for both Pro/e and Catia for years and even then, they were optional. Even after they moved to the PC. Sadly, the high programs could not even utilize the STEP and IGES files with their strict history based systems.  Most of the mid-ranged programs even developed native translators for Pro/e, Catia and NX.

The introduction of MBE is where the PLM folks started driving engineering. Boeing, which had the most streamlined and productive engineering system and standards in the world actually let Dassault with their new Catia 5 and PLM to take over their engineering.

This move was proven instantly fatal with Catia 4 and Catia 5 being completely incompatible! This one fact cannot be overlooked. It shows an incredible lack of understanding of the purpose of engineering.

That put Boeing on a downward path and now Engineers were struggling to utilize a very convoluted system.

Now, I have to tell you small companies did not fall into this trap, only those that were stuck with the high-end systems. As they moved to the PC they still were very top heavy and took years to implement the productive enhancements of the mid-range products.

The mid-range products designed circles around these high-end systems and still do.

Good God, Joe, what the hell has this got to do with Engineering and Manufacturing? Be patient my friends!

As PLM took over the management of engineering the solutions they gave engineering were not working. Starting with utilizing the model as the design authority. They started adding Band-Aid after Band-Aid trying to make this work. Suppliers just worked around most of the silly, not thought through requirements.

Can the 3D Model Be Used as the Design Authority?

Compare and Validation Programs? Band-Aids for Self Inflicted Wounds!

Ooops, did I accidentally reference manufacturing??

Yes, I did.

We are now defining engineering documentation driven by the PLM folks. The draftsmen were being let go and replaced by degreed engineers that have no experience with engineering documentation.

Ah, any ties to the past knowledge to engineering documentation was soon gone.

The PLM folks were now the experts.

This is where things get a bit dicey.

Somewhere along the line the PLM folks thought that engineers were involved in manufacturing and they thought that the documentation could be used directly in manufacturing.

This is just not how manufacturing works.

Engineering works in the abstract. Even though today the 3D model makes us think our designs are real, they are nothing more than cartoons. We still have to give the instructions on how to make and assembly the parts in a concise, complete and unambiguous format.


Note: I have realized that the 3D model is as close to reality man has ever been. We should treat these as we do the manufactured part. We need a part mark system of some sort on the 3D model itself. This would eliminate much of the problems with PDM.

The Embedded Title Block! A PLM Solution!


This is the point the PLM folks will never understand.

I see this fellow pushing a “live” BOM 3rd party program. What in the world is the problem he is trying to solve? I have asked him a few pointed questions. He said it gives purchasing live data to get ahead of the design. I chuckled at his ignorance of the engineering design process.

We have a multitude of 3rd party programs for the MCAD products. You spend thousands on Pro/e, Catia and NX and you have to buy 3rd product solutions?

Even the mid-ranged programs have a myriad of 3rd party programs to make the programs more effective.

The most incredibly 3rd party program is the Quoting program I discuss in this article. This product takes the concept of the PMI and tries to return it back to the AID. A bit of "Back to the Future"!

Quoting Tools: CAD Dimensioning Another Band-Aid for MBE!

The PMI is in format that has no dimensions beside a few limited dimensions. Since you have no idea what size the part is you have to have a 3rd party or the native program that allows you to dimension it.

So what has all this streamlined engineering defined by those that have never done and engineering accomplished?

You just have to go WTF. Is there no one with any knowledge even involved?

Okay, Okay, I know, I know I am still beating this fricking drum, and I suppose I will until someone wakes up.

Today we have no standard engineering documentation that being offered to the new 3D MCAD engineer. Many companies are struggling to define their own standards and are failing.

Engineering does the design. There are many things that have to be established before engineering starts work. You have the Industrial designers come up with concepts. When that is complete enter the configuration management. Working with engineering they define the requirements. Engineering sets up the groups to get the process in place.

Imagine how Elon Musk set up Tesla. Can you imagine? Let’s build a new automobile. He hired engineering expertise in many different groups, power train, chassis, interior, glass, electronic, etc. and went to work designing the new Tesla.

Now engineering would build prototypes of most of the not purchased components. Prototyping is not manufacturing. It is assuring the design is feasible. Now, manufacturing may look at the work to establish a process.

Now the engineering is not done until the documentation is done. PLM folks think that his can be a live link to manufacturing. They live in a pipe dream. Luckily the suppliers are much smarter than the MSMEs, PHDs and Infotech geniuses. They have to “MAKE” parts. They moved from the abstracts to reality.

Now to manufacturing.

Most of the larger companies have outside suppliers that make their parts. Now, these suppliers are always changing, there are large, not so large and mom and pop suppliers.

If a company does have inside manufacturing then this MBE system could work since it required management on both sides. If not, it is Murphy’s playground.

If you have to ask who Murphy is. Pack your stuff and leave today.

Engineering delivers the documentation. This includes the 3D model and any associative information. We do not care what format. It is delivered to the supplier as a file.

At this time, the engineering is done and the native CAD data and documentation should be archived and easily accessible. There is no released documentation that is not archived. There is no such thing as current engineering documentation. It is archived and available forever. I checked out the original linen drawing for the KC-135 for the first time since it was created in the 1950's. Purchasing, marketing, Tech pubs, even engineering should use this released archived data. Actually it is one engineering's main purpose to release the engineering documentation to the archives.

If we are smart the engineering deliverable will be outside the native CAD system in the form of a released document. That documentation will now be the only official documentation used by any other department. I explain the optimum document controls system in this article.

This is where engineering parts ways with manufacturing.

Engineering Documentation Today.

The documentation should be concise, complete and unambiguous.

All of the parts are ordered.

They start coming back to the company. Boeing demands inspection by the suppliers. This is a bit short sighted since parts can actually change between order and delivery. So, any parts that come in should be inspected to the latest engineering release on delivery. At least the mating features. Reassigning this responsibility is hugely responsible for incorrect parts and slipped schedules.

These parts are logged in! No, not by engineering but by manufacturing. They are experts in assembly. They will have planning orders and these parts will already be in the program. They will be delivered to the appropriate process and be assembled.

Rarely is engineering even involved. Maybe at the first article. But the manufacturing people are experts in their field and know what needs to be done. This is reality and not abstract.

Nothing makes an engineer or designer (in my case) feel more fulfilled than to see their designs become reality.

I have to tell you it is that simple.

I have found that someone came up with a quite bizarre acronym.

DFM (Design for Manufacturability)

I have been a draftsman for over 50 years and I was shocked to see this. Draftsmen were responsible for most of the form, fit and function design of every aircraft ever built and every drawing came out of he drafting group was designed for manufacturability.

I cannot imagine a group of people that had to come up with his acronym.

I will tell you they were not draftsman. We had engineers that oversaw the design process, design draftsman developing the form, fit and function design, draftsman creating the drawings, checkers reviewing the drawings for both design and drawing correctness, reviewed and signed off by the lead engineer.

Now you tell me which one of those professionals had to be told to design for manufacturability.

This one acronym alone exposes the lack of
professional knowledge and skill in the industry today!
 


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