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PLM (PRODUCT LIFECYCLE MANAGEMENT) AND PDM (PRODUCT DATA MANAGEMENT) DEFINED!
PLM (PRODUCT LIFECYCLE
MANAGEMENT)
What is PLM?
"Short for Product Lifecycle Management, it refers to a set of software tools used for mechanical design, analysis and manufacturing to support products from when they are first conceived through distribution and retirement. PLM is assembled from various software programs, rather than purchased outright as a single commercial off-the-shelf product. Once assembled, a well-designed PLM system will manage product specifications and formulas, provide production histories, create complete product genealogies, and track total product quality."
Who needs PLM?
It is not clearly defined who needs this, but from what I have read, it is a requirement for large multi-year design projects, designed and manufactured in different locations, with multiple suppliers. , Siemens (was UG) and Pro/E (high-end CAD) and Solid Edge (the only mid-range CAD) offer this capability. There are also a multitude of stand alone PLM products.
What was done before PLM. Oh yes we had drawings and on these drawing had the BOM, specifications and all the data necessary to manufacture the product. Yes, Joe is getting back on his soapbox. The 747 is a product that fits the definition of a product that would need PLM. The Airbus A-380 was a comparable product that used PLM in the design and manufacture. We have heard of the stories of errors in engineering and manufacturing on that project and now there are similar stories being told on some current projects, these errors don't cost millions, they cost billions in missed schedules and rejected parts. The problem: Using two versions of the same CAD product, Catia 4 and Catia 5. To manage a PLM system you need a large force of IT folks, hmmm, wonder who is behind this conspiracy.
I have again been approached to provide drawings of solid parts from large Catia user in the area. The vendor is in a bit of a donnybrook with the large Catia user, trying to get clear definition of the parts. The large Catia user sees no problems in the 3DMBD, yes (3D Model Based Definition) and PMI (Product Manufacturing Information) that they are providing. This has been an on going struggle for this company since the project started a couple of years ago. They even have a compatible Catia station, of course, no one is trained (6 to 12 month learning curve) on the software and they use it to only get the part models to KeyCreator. In the past they have had a hard time getting me the PMI, which is basically annotation GD&T in 3D space. This is not easy to view, depending on the complexity of the part, in fact, it can be a horror show and impossible to interpret. But now that I have SpaceClaim I can view this information and even put it into a drawing. I could make the drawings in SpaceClaim, but I am sure I will be required to create the drawings in KeyCreator, since that is the software the vendor uses.
Hybrid Modeling and PLM
With Siemens (UG) and Pro/E bringing out hybrid modeling modules incorporated into their software, they will be able to import models into the CAD package and use their PLM maintain the parts and assembles and even modify them. So now it will not matter what package the parts are created. This is truly the next step in CAD compatibility. All packages with have this modeling capability or they will not be in business. I still believe that IRONCAD offers the best of both worlds. KeyCreator is the best overall hybrid modeler since it incorporates 2D/3D wireframe, Surfaces and solids in one easy to use 3D space. SpaceClaim is by far the best for solids only hybrid modeler and is the only fully functional and most affordable Catia translator/modeler.
So are you ready for PLM?
PDM (PRODUCT DATA MANAGEMENT)
What is PDM?
Product data management is a category of computer software used to control data related to products. PDM creates and manages relations between sets of data that define a product, and store those relationships in a database. It is an important tool in product lifecycle management.
Who needs PDM?
Most of my clients are already using some form of PDM even if it is just Windows Explorer. And most of these clients are still smart enough to use drawings. The PDF's generated from the drawing of the part or assembly is used for quoting, scheduling, manufacturing, procuring, checking, reviewing, planning, refining, cost effect evaluation, new product definition, etc. This PDF can include all the data necessary to completely design this part or assembly. No need to have a special viewer since the Adobe reader is available to all. You can even include a part to view in 3D. The non-engineering folk really don't need the 3DMBD (3D Model Based Definition), they truly only need a drawing and the specifications. In my viewpoint this is the only thing that is necessary to be delivered outside the design engineering departments. Yes we do need to also deliver a 3D model of the part to manufacturing that should match the drawing. Yes, this puts a lot of responsibility on the design engineering group to make sure the drawings are kept current, but this is no different from the past. Many of the drawings started out as assembly layouts, from which the drawings were created. But for some reason, currently this is considered very time consuming expense until the parts start coming in wrong or mistakes are caught by manufacturing. Project cost over runs, delays, redesign, etc. are the result of not measuring twice and cutting once. Please feel free to read TO DRAW OR NOT TO DRAW.
Product data management is focused on capturing and maintaining information on products and/or services through its development and useful life. Typical information managed in the PDM module include
PDM Advantages:
The Drawing:
In the past the drawing was the total PDM package. It is as if it was a mystery how we made products. We did all the above with one document.
We had signature blocks:
Drawn: The name of the drafter/designer Engineer: The responsible Engineer Stress: The stress engineer Mfg: The manufacturing Engineer Mgr: The responsible Engineering manager
BOM All material and size and parts if assembly. Notes All specs for the materials or Assembly rigging instructions. Rev Block Kept track of all revision to the part.
Yes one document, compare that to now. You have to have a special software to view the PMI. 3DMBD had dimenstion all over, to the point where they are confusing to stive to review. The features that are covered by the profile tolerance are not dimensioned, leaving them to really be overlooked by the designer. I am now seeing parts that could not have gone thru all the above checks. Many parts could not be manufactured and many are not fitting at assembly. There are no short cuts to complete engineering procedure.
Enter the 3D model:
Many think the 3D model does everything. Sad to say it really doesn't. Yes, we can use the model for new products. But to manufacture the part, it has to be documented. Many of the parts I have looked at have been created by CAD jockeys and from the looks of them not reviewed for manufacturability. These parts have been rejected time and time again by the suppliers, or many times they have been done to only be not to fit in the assembly. Engineering is a time consuming endeavor. It has to be done as correct as it can be done. It has to have checks, and rechecks because "MURPHY'S LAW" is in full effect. I know this will fall on deaf ears. But if you supply the drawing and the solid model in the same package that is verified by the responsible design group you be assured that the correct part is being manufactured. From the looks of the results the 3D model is becoming more of a hindrance then an asset, at least in the current form of delivery.
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