Revisions in CAD/PLM/ERP: Old Problems or New Challenges?

by Oleg on June 7, 2011 · View Comments

I want to talk about the topic, which is actually is not very new – revisions. I was reading Autodesk Manufacturing Community blog – Vault 2012 Revision Block Integration. It made me think about the problem of revision in engineering software, how different software engineering and manufacturing disciplines solve it.

Revisions in CAD

The support of revisions in CAD has a long history. From the early beginning of CAD systems, engineers had a need to maintain revisions and changes in drawings and later in 3D CAD models. Because of CAD reliance on the file system, revisions where originally considered as something that “file system” can do. As a result of CAD files’ complexity, it wasn’t as simple as managing of Word file revisions. Companies were developed multiple strategies how to manage CAD file revisions. At the same time, revision must be part of every released drawing. Because of this need, CAD systems started to provide the support for automatic reflecting of revisions (and revision history) inside of CAD files and drawings. You can take a look on the How to make a Custom Revision Table? blog article to get an example of advanced revision reflection in SolidWorks. Other CAD systems can do a similar job from the conceptual standpoint. However, revisions are complicated. To handle them right manually is not a simple job. You can see the following SolidSmack Blog – How To Kill All Previous Revisions on a SolidWorks Drawing? as a good example of problems customers are facing on a daily basis. The last (and not only) led companies to develop advanced tools to manage revisions. It was the beginning of PDM.

Revisions in PDM / PLM

At the time PDM system started it was about a “vault” and “revisions”. The idea of documents (CAD) control was dominant. To put CAD files into the electronic vault (so called EDM, TDM or PDM) was a simple task, in my view. However, it raised few problems very fast – 1/not everybody in an organization can/want to use these DM technologies; 2/the output drawings (2D and printed in many cases even today) need to contain the information about revisions. Even if industry of PDM systems passed last 20 years of evolution, it is still about to solve revision/drawing update problem. You can take a look on two videos from Autodesk and SolidWorks presenting the same challenges and scenarios.

In parallel, the evolution of PDM into PLM raised the new set of problems. Product Lifecycle Management introduces an additional set of information. In addition to Documents, you are management Parts and Part lifecycle almost in 100% of PLM implementations. The problem now becomes not only how to find a right revision of CAD assembly, but also to find relevant revisions of Parts/Items. At the same time, Parts lifecycle is completely different from Document revision management. Connection between them creates another set of challenges for every company- how to relate a right drawing version to the right Part Number and how to manage these relations.

Revisions in ERP

ERP systems have a different pattern of the data and revision modeling. ERP is not actually managing versions. The fundamental difference is that ERP is managing “effectivities”. Revision is not something that makes a lot difference to ERP, except one small elements – ERP system needs to have a reference to a relevant version of document/drawing with the right information inside of drawing. It creates another set of challenges. The following videos present examples of integration between CAD/PDM to the ERP.

What is my conclusion? In my view, after all years of CAD/PDM/PLM, the issue of “revision” is still unsolved. Why do I think so? It is because the simple question like “where is my last revision?” or the question like “Where is the up-to-date document, which belongs to the product X?” are still not answered in many companies. Each system in the whole engineering and manufacturing software world has sort of a revision / version notion. However, the new challenge is probably the interplay of revision in different systems. It doesn’t really happen and PLM systems don’t seem to have a reliable solution these days. Just my thoughts…

Best, Oleg

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Tagged as: CAD, ERP, PDM, PLM, Revision Management, Versions

  • Oleg hi - i am not sure if the issue of revision is unsolved. I guess it is important to differentiate between the world of production (stored in ERP, but fed by data coming from PLM) and the world of product definition.

    In the world of production the part number is leading and depending on the type of industry and business process, it matters if there is a revision on the part number. The important part of the release process to ERP is, to assure that related to these parts the right documents for manufacturing are linked (or effective) . What the document revision methodology is at that time, does not matter so much - the release defines which documents are used for manufacturing

    On the product definition side of course the revisions are more important - as usually in this stage the part number/revision is not in target. In this stage you want to make sure when people collaborate around the same data sets, they know what is the actual revision and what to do with existing definitions.

    So far i haven't seen the problem as a real problem. The problem comes when you start implementing with a certain PLM software package - and this is mostly the case if you leave Excel out of the picture. 

    PLM vendors tend to simplify (or you can call it generalize) their software to support a mainstream basic scenario for revisions - but what is mainstream - is it engineering to order, built to order, make to order ?

    My thoughts - yes it is not easy to implement if you look to standard vendor capabilities, but using common sense (and sometime unfortunate a little customization of the software) will help you to overcome this issue  

  • beyondplm

    Jos, thanks for commenting! Sorry, I somehow missed this comment in my previous communication. I think, the fact it is not so easy to implement means the problem is still there. I agree, there are multiple use cases and scenarios. The software is complicated. Some of packages on the market is oversimplifying and some other packages are too complicated and requires weeks of consulting. It represents the problem... Just my thoughts. Best, Oleg

  • Alex van der Linden

    Oleg,

    This is a very actual topic in my environment. Thanks for your story.

    I'm also interested in insights about how to deal with changes/revisions in the context of a (big) product structure. What is the impact of a new revision on its 'parent' in the product hierarchy? Should a change 'fade out' when it is FFF compatible (interchangable revisions)? Or should a change only 'stop' at predefined configuration items / end items?

    Insights and pointers to related articles/videos are very welcome.

    Regards,
    Alex van der Linden

  • beyondplm

    Alex, you are welcome and apologies for some delay in communication! I think FFF is mostly related to BOM/PS. With documents, the idea of Parent lock means you cannot change anything that connected to the locked /released parent. Best, Oleg

  • Imoriarty

    A true PLM solution should be with a doubt where an enterprise looks to find the latest revision of any data associated to a part/assembly. However, I agree that many PLM solutions that are out there today either can not perform this task or do it poorly. PTC's Windchill solution can manage most major native MCAD and ECAD file formats as well as any documentation that may describe a part, assembly, or BOM. It can intuitively manage all of these files so that when a change is made anywhere it is reflected everywhere. This results in a single source of truth that a company can trust and rely on to be the latest and greatest revision, and let's face it, how useful is a PLM solution if you can not trust that it is properly managing your data and you are working with the latest revision.

    Being able to manage all file types intuitively and associatively, allows companies to build out a true complete BOM that can be easily transfered to ERP. Most companies today are manually tracking and updating changes to a complete BOM that is being stored within their ERP, which does not manage design content or change well at all. PLM solutions that do not have the ability to manage this complete BOM are missing the mark.

  • beyondplm

    Imoriary, thanks for your insight. I think, the problem is in a "single source of truth". It is hard to maintain, and it is costly and complicated. What if you have multiple PDM systems? The best PDM system to manage CAD data today normally produced by CAD manufacturers. Multiple PDM soon becomes a problem... Just my opinion, of course. Best, Oleg

  • Hi Oleg,
    what I notice is that a lot of people  mix history up with revision Management
    Important  for revision management is for example:
    Impact analyses
    Form Fit Function
    etc

    regards

    Menk Slot
    www.plmconsult.nl

  • beyondplm

    Menk, Thanks for mentioning that! Agree- this is absolutely important. Especially FFF is something that interconnected with revisions. The topic normally called "interchangeable revisions". Best, Oleg

  • Fernando.

    Very good article. You have described exactly what's happening in the company I work.

  • beyondplm

    Fernando, Thanks for the comment! Best, Oleg

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