Component documentationOptimization

 

You implement optimization in PP/DS after an infinite MRP run has been executed. During optimization, the system carries out finite scheduling to achieve a feasible production plan.

Implementation Guidelines

To implement optimization in PP/DS you must first carry out the following IMG activities:

  • You have maintained the master data for optimization in Customizing of the Basis Settings under Start of the navigation path Optimization Next navigation step Basic Functions End of the navigation path(for example, the network links to the optimization server and the maximum number of users).

  • You have defined an optimization profile in Customizing for Detailed Scheduling or under Start of the navigation path Production Planning Next navigation step Environment Next navigation step Current Settings Next navigation step Maintain Optimization Profiles. End of the navigation path

    In the optimization profile, you define all the criteria for executing and controlling of optimization in PP/DS. For detailed information about different set-up options see the field help for the optimization parameters in the optimization profile, and the documentation on the IMG activity in Customizing for the detailed scheduling planning board.

Integration

The optimization is integrated into the following applications:

You execute the optimization interactively in the planning board and planning table, and in the background for the production planning run.

If you have called up the optimization in the DS planning board or in the product planning table, the system adopts the optimized schedule into the current simulative schedule when the optimization has finished. If you execute the optimization in the production planning run or in the DS planning board, you can elect to save the planning results either as a simulation version or in the planning version.

For detailed information and additional restrictions, see SAP Notes 1171154 and 712066.

Features

Optimization Criteria

You can use optimization to optimize the production dates and the resource allocation for operations, based on the following criteria, which you define in the optimization profile:

The optimization determines a schedule for scheduling in the optimization range in which a result as close as possible to the desired result, for example, the minimum setup time, is achieved. To do this, the system varies the start dates and the resource allocation for the operations.

Principle of Optimization

The optimization evaluates a schedule; that is, it evaluates the dates, the resource allocation and the sequence of activities, based on the objective function. The objective function is the sum of the above-mentioned weighted time and costs (optimization criteria) that are especially critical for scheduling. During optimization, the system tries to reduce the value of the objective function; that is, it tries to find a schedule in which the various times and costs according to their weighting are as low as possible. In general, it is not possible to fulfill all the scheduling objectives to the same extent. For example, a reduction in the setup time could lead to an increase in the makespan.

The optimization criteria weightings you use to achieve good results depend on the planning situation and your corporate objectives. You can control the quality of the solution via the processing time that you allow for optimization. The rules of thumb are as follows:

  • The more time that is available, the better the solution will be

  • The more extensive and complex the problem is, the greater the time required

Constraints for Optimization

During optimization, the system considers the various constraints in the schedule. A distinction should be made here between hard constraints, which the system must adhere to, and soft constraints, which the system tries to adhere to, but which it violates if necessary in order to find a solution that complies with the hard constraints. The working time for a resource is, for example, a hard constraint: The system is only allowed to schedule activities in working times. Requirements dates/times from sales orders are soft constraints. The system is also allowed to schedule receipts after the requirement date. These delays can, however, be minimized during optimization.

Earliest start date for the optimized schedule

Before the optimization, you specify the earliest date on which the optimization function can schedule the activities. You cannot enter an earliest start date that lies in the past.

Campaign Optimization

You can also execute campaign optimization in the optimization.

Simulative Optimization

You can execute a simulative optimization and adopt the optimized schedule into the operative planning version.

Logs

If you choose the transaction /N/SAPAPO/OPT11, the system displays a list of all optimization runs. The PP/DS optimization runs are created for the component DPS. For each PP/DS optimization run, you can display the results in the following logs: