EPDM Workflow and Rev Blocks

The SolidWorks Enterprise PDM (EPDM) workflow can be used to automatically show revision history by populating the revision block table on your drawings.  By configuring a set of variables to hold current and past revision information, and setting those variables in a workflow process, you can free designers from the tedious process of putting revision block information into SolidWorks each time a drawing is approved. 

For the purpose of this article let’s assume that the following four properties need to be written to each row of the revision block table: Date, Description, Revision, and Approval Signature.  The first time a drawing goes through the workflow, all of these fields are blank, so only the first set of properties (the set for the initial revision) needs to be written.  Keep in mind that the Increment Revision action in EPDM is always the last action in a workflow transition.

This EPDM transition is not difficult to setup; you just set variables and increment the file’s revision stamp in the database.  But when the file makes a second, third, fourth, etc. pass through the workflow, a more complex set of actions is needed for the workflow transition.  Since you want to write the most recent change information as the first in the list, you need to shift the existing revision history to make room for the newest entry.  So you’ll copy 03 to 04, 02 to 03, 01 to 02, and then insert your new information into 01.  Note that you have to copy the next to the last set of revision data over to the last set of revision data first (if you start by copying 01 to 02, 02 is overwritten before you can copy it to 03).  You also need an extra set of revision information (one set more than you plan to keep on the revision block) to accommodate a potential rollback.  So if you plan to show five rows of revision history on your drawing title block, you need to have 6 sets of variables in EPDM (6 sets multiplied by 4 variables per set would be 24 unique variables).  This is not as difficult as it may sound.  Once a pattern has been established, this fits the cliché, “next verse, same as the first.”  The image below shows three revision history rows being kept on the drawing/data card. 

Finally, make sure that all the properties that you are writing to the data card are mapped to the SolidWorks file properties.  It is critical that the appropriate properties are mapped to $PRP (file) and $PRPSheet (drawing sheet) to get the results you’re shooting for on the drawing.

Tags: drawing, Enterprise PDM, EPDM-workflow, revision history, SolidWorks, workflow