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Reprocess Limits#

Overview#

The Reprocess Limits features aims to provide the possibility to define the maximum number of times a material of a given product or product group can be reprocessed at a given step, so that when a material reaches the configured limit, it won't be possible to process it anymore on that step.

Background Information

Reworking or reprocessing materials is a common practice in manufacturing to correct or prevent defects and non-conformities that might appear during production.

However, repeated reprocessing can compromise product integrity and quality and it's common that manufacturers specify the maximum number of times a material of a given product can be reprocessed at a given step.

Concept#

Every time that a material is tracked-in to a step, the material and its descendants are checked against the SMTReprocessLimitContext smart table. If there's a match in the smart table, the material's SMTStepCountLookup attribute will be checked:

  • If the limit has been exceeded: block the material from proceeding by throwing an exception.
  • If the limit has not been exceeded: update the material's SMTStepCountLookup attribute.

Performance

Implementing this feature required attaching a DEE to the Material's track-in operation. We took every effort to make this DEE as lean as possible by batch loading/saving and caching absolutely everything, but if you're struggling for performance and are not using this feature, disabling the SMTEnforceMaximumReprocessingLimit DEE which powers this feature might help.

Setting reprocess limits#

Lets assume that a user wants to define that every PCB (material) from the Product "SMT_Product" can only be processed 1 time at the SMT_SPI step. This means, reprocess is not allowed at the SMT_SPI step. Once this limit is reached by a given PCB, it will not be allowed to be reprocessed (tracked in/out) at that step anymore.

Let's start by heading to the administration tab...

...and selecting the SMTReprocessLimitContext smart table.

Let's add a new entry.

Configure the smart table according to the previously explained use case. Notice how the Product, Flow, Step and Maximum Reprocess Limit are configured.

Reprocessing, not Processing

Please note that this feature only limits reprocessing of materials, not the initial processing step. This means that if you want to completely disallow reprocessing of a material (as in our example) you should set the limit to 0. The material will still be allowed to be processed once at the step, but that's it.

Executing reprocess limits#

Assuming that the feature is correctly configured and you have a material that has been already processed at the SMT_SPI step...

... if we want to process that exact material once again at the SMT_SPI step, the system will not allow it because we defined the reprocess limit for that step as 0.