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…