THE 3D CAD DATA MANAGEMENT MESS
In engineering we do not handle data we handle documents!
I was working with a company that provides a software tool to validate 3D parts, and I thought why in the world do we need a tool like this?
We do things a bit different today; we design solid models or what we could call 3D Drafting. Now we can create an AID (Associative Information Document (drawing) from that model, but it seems like it would be a lot easier to just send the 3D model out with a couple of critical dimensions and material specifications. But there are problems with maintaining that data. Each CAD program has a PDM (Product Data Management) system, there are even third party programs to track changes in the parts and assemblies. From the input I get from my associates and customers this new system is causing some very serious problems.
We Do Not Create Drawings!!!
This article was written before I realized that we do not create drawings! What do we create? We create what I have coined the AID (Associated Information Document). I describe this in the following article. I do recommend you read this and every time the word drawing is used, realize that we create something quite different and much, much more simple and easier.
Since we now design in 3D and "NOT" in non-associated orthographic views generated on a 2D plane (the drawing) we do not need the draftsman!
Boeing got rid of their complete drafting system years ago. What did they eliminate? They eliminated the standard documentation process that was developed over 80 years, replaced by the failed PLM/MBE/PMI experiment. I now realize that they had to eliminate any opposition to this new concept sold to them by Dassault that had how many years in creating standard engineering documentation? Not realizing that the total purpose of engineering is to deliver complete, concise and unambiguous documentation to manufacturing. Drafting is a required part of engineering, it was responsible for the release of the "standard" engineering documentation.
Today we do not have an engineering documentation standard.
We also have the MBE (Model Based Enterprise) which is nothing but another Band-Aid for ineffective document control that has caused this data management mess.
The Native 3D CAD file
cannot be used
Now back to the subject!!
"The only purpose of engineering is to deliver concise, complete and unambiguous documentation to manufacturing"
PROVEN ENGINEERING PRACTICES
When I went to work as a draftsman for Boeing there were standard engineering practices that had been in place for Decades. We did the drawings; they got checked by a drafting/design checker for fit, form, function and standard drawing practices. They were marked up in yellow for correct and red for the errors. The drafter did the pickups (corrections) and then they were rechecked, until the checker was satisfied. Then it was taken for review and signatures from stress engineering, materials and manufacturing, with a final signature from the lead engineer and engineering supervisor.
The completed drawings were photographed into the microfiche system. Many hours were spent looking for all the drawings that made up the assembly configuration that you were going to modify or redefine as a new configuration.
The drawings were then released to manufacturing to create their planning procedures. Planning actually created their own documents on how to manufacture the parts or install or rig the parts/assemblies. As they established an assembly line, they had liaison engineers to help solve any problems. When there were problems the liaison engineer would resolve the problem on site and create a rejection tag. This rejection tag would go to the responsible engineering department and an ADCN (Advance Drawing Change Notice) was created (A size sheet) or they directly revise the drawing with a DCN (Drawing Change Notice). When the drawing accumulated many ADCN’s they were incorporated them into a new revision with a DCN or Revision. These changes were sent out to all suppliers.
TODAY’S ENGINEERING PRACTICES
Update: May 2017: The industry need a documentation standard!
In the beginning of 3D CAD its only product was a
drawing delivered as a print (1980-2000). Soon the
3D model by incorporating surfaces and solids were
used for CNC and 3D printing in 1990. But what the print was
still delivered with the 3D model until 2000 when the PDF
became popular where we could deliver the drawing
and model by email. But the
industry was developing another solution due to the
lack of PLM to effectively handle, at that time, the
paper print: The MBE
(Model Based Enterprise) that eliminated the need
for the drawing and opened the door to using the
native file as the engineering deliverable with the
PMI (Product Manufacturing Information) basically a
3D drawing. Well there are 5 popular 3D CAD systems.
This eliminates any chance of having standardized
documentation. One day, the Boeings, Airbus, all the
automotive companies, etc. will get tired of wasting
all of the time and money and demand a workable
Years ago Pro/e was released. It had separate parts, assemblies and drawings. That is when the data management trouble started. You had to maintain all of those files, and PDM came into being. Now this is not really a problem with a small company where you have 3 or 4 designers or engineers and they are in close proximity. The problem starts when you have people in different locations accessing the information. Then add vendors with OEM parts and you have a new problem of implementing a massive program of standardization. From sending a manila folder with some clearly defined drawings to now having to make sure the recipient has all the necessary software to evaluate and use the information.
The basic problem with todays data management is that we really manage documents. There are two documentation streams for engineering, internal CAD parts/assemblies and the documentation required for other departments. PLM is trying to handle both streams as one. Sadly, never the twain shall meet and that is the basic failure of any PLM system.
There are a few CAD systems that have all of the parts/assemblies and drawings in one file!! What if the CAD world would have standardized on that requirement instead of letting the CAD vendor define our process because it was "easier" to program? But even then we would still need a standard deliverable for outside the engineering CAD system.
It truly is time to take back control of engineering and quit letting the CAD vendors with their vested interest define the process, locking companies into incompatible unique systems. We need to set a standard and demand that the CAD vendors meet the requirements. It really is very simple. Today, there are no people in charge with the necessary applicable knowledge or responsibility to make it happen.
Update 4-3-15: The PLM solution defined in the above article becomes a reality.
Years ago I envisioned a Web page for each part or assembly. This would be done by a document control group outside of engineering, utilizing a defined standard release package or bundle from engineering. This is nothing more than modifying a template. I never had the resources to bring this to fruition.
Today we have that solution and more!!
Today we have that solution and more!!
Onshape is by far the most exciting developments that has been introduced to the CAD industry. Today you can have a standard deliverable with the latest information directly accessible to other engineering personnel, purchasing, marketing, manufacturing, tech pubs, etc. managed by a document control group. You could have non-engineering personnel maintaining this information, let engineers get out of data management and do their work. I will have an article on the benefits of this concept utilizing Onshape!
When we talk about data management what are we talking about? We are really talking about document management. The part model, of course, the assembly, the DRAWING, oh yes the drawing. Even if you don't do a drawing you have to include specifications, such as material, GD&T data for inspection, processes, etc. If you use a Pro/E paradigm program you have at least 3 documents to maintain with each assembly. These documents or files have to be available to manufacturing to create and inspect the part or assembly. Now we add an inspection document. Catia has a program called Enovia that does this. I am sure Creo and NX have their programs, and I know there are many 3rd party programs available also. Now the problem is that you need software to read this. And now you have to coordinate with your vendors to make sure they have all the programs to make sure you can utilize the data. Now you can imagine the initial and ongoing costs added to manufacture these parts.
Engineering Document Control is Bottom Up!
The Value of the Drawing!
A drawing is basically an inspection document, but offers much more than that. Completely detailing a part offers an incredible check on design from the designer as he creates the drawing. At this time we focus on mating surfaces and disregard the rest of the part. But I have detailed many of these parts and I can personally tell you that if they completely detailed the part, they would find errors and may even had seen a better design that would have been much easier to manufacture. Much of the non-related features were very difficult to make. The drawing becomes a design, easy to view checking and inspection tool. In the past we had drafters doing the design with an engineer managing multiple projects. Now they dump an engineer on a 3D CAD system and let him work on one part at a time, when a drafter has the experience necessary to communicate the information to manufacturing. I feel this is an incredible waste of talent and experience.
If a part is
difficult to detail (dimensioning)
How do we do changes in today’s Engineering practices? Today we are using the solid model as the authority for the part. That means that part or assembly has to be kept up to date and available to manufacturing. Manufacturing has to have the tools to evaluate and use the information. This has become a nightmare. A drawing takes no more than 2 to 4 hours to detail from a 3D model, of course there are more complex parts but most can be done in that time frame. Yes we have to maintain the drawing. But if we made the drawing, as in the past the authorizing document, we would not need all the confusing PDM software outside the system.
This change in focus has caused a multitude of problems. Let’s go back to the ADCN. How does the liaison engineer fix the part and notify the originating engineering department. No drawing to modify and needs special software to view the part. So he has to have a way to do this and fix the error and get that fix to engineering. Now they have to modify the part, and get it into the system as soon as possible. Since we have no drawings we have to work directly on the part and make the new part available to manufacturing so no incorrect parts will continue to be made. Now here is where things can get very tough.
THE PROBLEM WITH HISTORY BASED CAD
The rejection tag gets back to the originating engineering department. The original designer has quit, fired, retired, transferred, etc., so another designer has to rework the part. I have worked on history based design systems like Creo, Solidworks, Inventor and Solid Edge and it can take 2 to 4 hours just to figure out how the original designer made the part. Then he can modify the part as required. Many times some actually rework the part; imagine how dangerous that would be. If some other important features was missed. This can become a horror show maybe even requiring a compare program. This is where the drawing is so important. It is a picture in stone in a PDF.
Let’s say we only need to change a few fillets. On an AID (drawing) we just create an ADCN, going to the correct locations and show the change. No need to remodel the part. That can be done later when you incorporate the ADCN or do a revision to the part as we have done in the past. Manufacturing gets the ADCN and modifies the part. Modifies the part? Now how do they do that? Do they have the correct CAD software, probably not, but with the focus on hybrid or direct face editing they can easily make the changes, probably easier and faster than the neophyte 3D CAD engineering. Using the drawing they can now be sure to be creating the correct part. Even with this assurance of the correct information you would have to use a Validation Tool to make sure that the part had only the required change. The a validation software inspection tool would also be necessary in the design departments to see that the engineering changes were implemented correctly.
The solution is not more complex data management systems to handle what those that have no applicable knowledge of the engineering process are tying to create. But to standardize the documentation in a format that can be easily accessed and effectively utilized.
We need a product that can include all the information in one file. There are a few CAD products that can do Assemblies in one part file. This is called the Single Model Environment.
Now how could a switch to IRONCAD to benefit your data management problems. History based solid modeling is a very good design system and many of us enjoy using it. But programs like Solidworks, Pro/E (who just purchased CoCreate) and other programs are fast learning they need hybrid (direct face editing) to get the job done. IRONCAD has been on this track for a very long time and has proven it can virtually take any data, 2D/3D wireframe, surfaces and solids and utilize it. So you could translate or have IRONCAD take the native data and create the drawings in a separate drawing module.
But imagine how easy it would be, one master file available to everyone. IRONCAD is very inexpensive solution for the engineering to standardize. It is easy to use and offers incredible unlimited flexibility.
INOVATE, IRONCAD's modeling only package offers integrated history and direct editing functionality. But also includes integrated realistic rendering, animation, kinematic with collision, drag and drop design from standard and customizable catalogs.
IRONCAD adds sheet metal design with non-native unfold (INOVATE also has this), detailing, advanced surfacing and add advanced solid modeling functionality.
For more information on Compose!, INOVATE and IronCAD.
Please visit our Leverage Your Engineering Data series:
ZW3D also offers increase productivity. It is very much like the Pro/e clones like Solidworks but offers much more flexibilty with its multi-object environment (where top down design is the basic process) to the integrated drawings.
It offers a multitude of capabilities beyond the standard modeling by including Class A Freeform Surfacing, Precision Morphing, Robust Reverse engineering and much more. They are one of the few integrated CAD/CAM programs offering full associated CNC.
Starting rental price of $375.00
WARNING: ZW3D is a professional 3D CAD engineering package and it is not recommended for those who are not engineering professionals or students with no prior 3D CAD experience. While we will help you get started we are not equipped at this price to teach you 3D CAD from scratch or engineering design. Don't let this low price fool you.
We sell and support IronCAD and ZW3D Products and provide engineering services throughout the USA and Canada!
If you are interested in adding professional hybrid modeling capabilities or looking for a new solution to increase your productivity, take some time to download a fully functional 30 day evaluation and play with these packages. Feel free to give me a call if you have any questions or would like an on-line presentation.