Resources can require a setup time to change the configuration between different setups/configurations. This models the time required for cleaning, installation of new tooling, re-calibration, feeding new raw materials, etc.
Such changeovers can take an considerable amount of time, and thus have an important impact on the production plan. The production planner will need to group production orders together in batches such to find a balance between reducing the changeover time and extra inventory caused by such grouping.
This example models a simple painting shop. Products can be painted on 3 equivalent painting lines. When a painting line changes color a setup time is required to clean the machines.
A number of data fields are required for this model:
- The setup matrix rule can define an extra resources that is required to perform the changeover. This can a technician that will change the machine configuration, some calibration tooling required for validating the new setup, etc…
- Resource table refers to its setup matrix.
- Operation-resource table defines the setup an operation requires on the resource.
- The batchwindow field in the operation table defines the time window used by the solver algorithm to reduce changeovers. The solver algorithm will scan for opportunities to create batches within this time window before and after the requirement date.
The generated plan drastically changes as soon as a batching window is specified. The changeovers between operations are shown as a black line. Only a part of the plan is visible in the screenshot.
- Plan editor without setup optimizationThis plan has many changeovers and a low inventory.
- Plan editor with setup optimization and large batching windowDemand is now produced in very large batches. This results in a minimal changeover cost but large inventory costs.
- Plan editor with setup optimization and smaller batching windowBy reducing the batch size window, we obtain a plan that reduces the changeover cost while avoiding excessive inventories.
Note that the setup optimization is only available in the Enterprise Edition and Cloud Edition. The Community Edition respects the setup times, but doesn’t have the optimization algorithm.