Creating Solver Settings - General Tab
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Open the
Solver dialog box by selecting
Schedule > Solver.
Note: If you have not selected batches before opening the Solver dialog box, you can still edit the settings. In this case, you only see a Close button instead of the Apply, Cancel, and OK buttons.
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To save a new configuration, click
Save to the right of the
Settings field and enter a
configuration name in the dialog box.
Note:
- Select <new> to display the default settings.
- To enable the CIP solver, select CIP in the type list. When you select this option; the CIP tab is displayed, where you can specify the CIP solver settings.
- If you want the solver to be displayed in the Schedule menu, select the show in menu check box.
- To always show the message log after solving, select the with messages check box.
- Select the scheduling approach: as soon as possible or just in time.
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In the Options section, specify this information:
Option Description solve current schedule If you want the batches' current position on the planning board to be used to find an initial solution and objective value, select this option. If you select this option, the feasability of the selected batches' configuration on the planning board is tested. This option is useful for two reasons:
- An initial objective value is established. Therefore, solutions that are worse than the current solution on the planning board are not returned by the solver.
- If you select solve via local search, an initial solution is required before a better solution can be found. To define an initial solution, you can select solve current schedule.
solve current sequence If you want the batches' current sequence on the planning board to be used to find an initial solution and objective value, select this option. Whether a solution has been found or not by the first step, the joining of the batches on the planning board is tried in the direction that is specified for the solver setting as soon as possible. Therefore, gaps are removed and small overlaps in batches are fixed. The current sequence phase is required before a solution that is better or equal than the first solution can be found.
solve all sequences If you want an improvement of the solution to be searched via trying all possible sequences in a systematic way, select this option. A solution better than the solution that is found by the first two steps, if any, is searched. All possible sequences of batches on all possible resources are tried. If a sequence has a better objective value than the current best solution, the new solution is retained and a better solution is searched. The search can be stopped in these situations:
- You click Stop.
- A time limit or another limit that is defined as an abort criterium is reached, for example, the local search start time.
solve via local search If you want the all-sequences search to be aborted after the indicated time when a solution is found, select this option. This solution is used to find better solutions in a different way. The solve all sequences search phase is aborted by this search phase after the number of seconds that you have specified or, if no solution is found after this time, later. In this case, as soon as a solution is found by the previous step, the search is started again. With this option, a solution can be searched without all sequences being systematically tried but using other rules. If you do not specify a time limit in the Configuration tab, this phase usually aborts after a few hours, when the solution cannot be improved anymore using any of the available rules. To improve the performance, you might want to run the search for a night. We recommend that you use this search when no better solution is found anymore using the solve all sequences option. The default time limit for starting is 20 seconds by default, but can be modified. In some cases, using this search, you may not find a solution or you might want a solution that adheres to the default strategy that is used in the third step, for example, "sequence priority batches" rules. In the latter case, you can clear this option. The "minimum improvement next better solution" setting is ignored by this search phase and the first step is always used.
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Select the strategies for the solver to work with.
See Solver Strategies.
- Click the OK button to save your changes and close the window. Alternatively, continue populating tabs on this window.