Optimization 

Use

You can use the optimization to optimize the production date and the resource allocation for operations, based on the following criteria:

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. You can also execute campaign optimization in the optimization.

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

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.

Prerequisites

Features

Optimization principle

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 various weighted time and costs 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 total lead time.

Optimization procedure

How suitable an optimization procedure is in finding a good solution, depends on the scheduling problem. You can choose between the following optimization procedures:

This procedure is suitable for complex scheduling problems in which many interdependencies and constraints have to be considered, and where it is difficult for the planner, for example, to find a feasible solution by scheduling interactively in the DS planning board.

This procedure is suitable for scheduling problems in which the planner is faced with the problem of finding a very good solution, and not just a feasible one. A typical use for this procedure is in establishing an optimal sequence based on the setup of operations.

Which optimization procedure and which weighting of optimization criteria you use to obtain good solutions, is dependent on the scheduling situation and the organizational goals. You decide on the quality of the solutions by setting the processing time for the optimization. The rules of thumb are as follows:

Constraints for the optimization

During optimization, the system considers the various constraints in the schedule. In doing this, it is necessary to differentiate between hard constraints, which the system must adhere to, and soft constraints, which the system tries to adhere to, but which the system 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. Requirement dates 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.