Last week I held a webinar about the differences between location vs. state-based permissions of files to outline some of the fundamental issues with associative CAD data control. Many companies today still manage shared data within their network infrastructure, which is controlled by IT's group policy. This means that the IT department has to be advised to set a specified, static hierarchy of access for folders in order to control who can change/overwrite controlled data.
For example, files that have been "approved" and are now released for manufacturing are physically relocated to a "Released" folder by specified parties whom have been given "rights" in order to ensure lockdown. This process of moving data was trivial in the days of flat files like Word, Excel and simple 2D/3D CAD. However in today's associative design world, files are no longer flat and, in fact, can be referenced in a complex parametric framework. This "network" of connectivity is CAD's greatest strength and weakness when it comes to updating and controlling the data.
The "Save As" Conundrum:
In the flat file days, a slight modification to a document/drawing was as easy as a File, Save As, renaming the file and editing it to reflect the changes. This procedure is still very common and has bitten every single parametric CAD user since the complexity of references in now in play. What was a trivial copy and rename procedure now only changes the name to which the existing references point to and modifications to sub-components or in-context features are now reflected to all associated parties. I wrote a post about PDM: The Conduit to CAD Efficiency to highlight how essential it has become to incorporate PDM into the design process when using a tool like SolidWorks.
Network Move & Copy/Delete Loss:
Another flaw that can come with having to change a file's venue is the issue of move/copy when working with files on a network drive. Despite backups and the ability to have a network recycle bin, users often are unaware that performing a "Copy" is far safer than a "Move" especially in the event that a connection issue arrises causing a corruption or loss of files. This, I'm sure, has happened to more than would like to admit. Loss is not completely avoided by the copy vs. move either since most whom perform a copy will go back and delete the original, keeping the only the copy in the new locked down folder. This system of changing venue is littered with pitfalls and procedural failure resulting in possible file loss and/or corruption.
Regardless how the physical data is controlled, company procedure typically dictates the "who/what/where and when" of design data. Companies attempt to mimic their internal procedure with folder structure and due to the static nature of securities on folders, file venue must be changed in order to carry out the design data's "Rules of Engagement". What is desired is a way to have folder permissions modify based on the stage of design the current file is at.
PDM Control Environment:
Among the many capabilities most PDM (Product Document Management) systems bring like automatic version/revisioning, serial numbers, notifications, etc, a new layer of security is also present and can parallel the folder-based control similar to that enforced by IT's group policy called "States". States are part of a procedural flow chart that allow securities to stay dynamic and follow the design process without the need of a venue change.
Removing the need to move files to modify security facilitates other aspects of procedural policy to be carried out. For example, staging a common folder layout for every project (Mechanical, Electrical, Software, Documents) without having to create folders for every revision and/or state. It also removes some, not all, the potential human error that comes from moving and deleting files on the network.
It is important to note that state and folder controls are not mutually exclusive and can be used together within the PDM environment. In fact, moving or renaming files inside PDM is recorded and maintains all those references without abandoning or overwriting previous changes. The overhead of file management is a huge productivity drain on every engineer and automating foundation access and control avoids these file-centric problems that surface in everyday design.
One of the biggest mistakes I see customers do when implementing a PDM system is to simply move the exact same folder structure and securities off their network drives and go on "business-as-usual" inside the vault, moving files to control access. So stop being file groomers and let states-based securities assist in part of the process! ~Lou