General information PDM

There are several possible solutions for the communication of administrative product data, e.g. between PDM systems. Deciding is, whether the communication takes place synchronous (online) or asynchronous (offline). Synchronous communication essentially deals not with the replication of data, but with direct access. Therefore, mostly the techniques CORBA (OMG, see also www.ivip.de) and XML (W3C, see also www.PDTnet.org) are used. Asynchronous communication, on the other hand, works by replicating data and sending it as files. There is currently no alternative to the STEP format. The theoretically available XML format is, compared to STEP files, not favorable for several reasons as, e.g., file size and the possibilty for pointer definitions (see also www.PDTnet.org).

The area of PDM data exchange shows by far not the amount of experience as the CAD area. This is, amongst other things, caused by the fact that the electronical exchange of PDM data is just being started in practice. What makes it even more difficult is, that the communication problems are not caused by false settings or lack of quality in the processors, but rather are of a sematic nature. This means that the sender uses attribute values, which possibly have no or a completely different meaning for the receiver (e.g. approval state C). Since in many PDM systems the used attributes of many objects are pre-defined company-specifically in order to control workflows, not designated values can not be assigned. Such values either have to be adapted (mapping) or need to be stored in special tables for user values within the PDM system.

Communication problems within the PDM thus are mostly not processor- or system-specific, but company- and process-specific. Hence, a solution can only be provided by a cooperation- or project-specific agreement. Regarding adaptions (mappings), software modules are available e.g. by ProSTEP, which can operated in chain before a reading processor or after a writing processor.

Specific Best Practices and recommendations for certain system combinations can seen from the profitability report of the 6th STEP Processor Benchmark for PDM data exchange.