Use

This type of scheduling is used especially for production lines. In takt-based scheduling, the system calculates the lead time of an order not from the duration of the line activities, but by multiplying the number of takts with the takt time. The takt time is therefore the reciprocal of the rate.

This type of scheduling allows you to schedule a large order volume, as the system does not have to calculate the durations from the routing, but only creates the capacity requirements for the line resource.

In flow and repetitive manufacturing, the materials remain for the defined takt time in a takt of the line, to be processed. The execution times that are calculated from the routing may vary from this takt time. Therefore takt-based scheduling produces a more exact result for takt-based flow manufacturing, than lead time scheduling.

Integration

Takt-based scheduling is carried out exclusively in the SAP APO system. The SAP APO system uses the following master data from iPPE line design and the line resource:

The operating time of the line, which you define using the line resource.

The number of takts (processing stations) that a material has to pass on the production line. The system calculates the longest (critical) path through the line structure, which you have created for linear line networks. For line networks with groups of alternative lines, it uses the parts of line networks to calculate the processing path for the product being planned. See also: Creation of a Line Structure for a Line Network with Alternatives and Creating a Part of Line Network .

The base rate and the production rate valid on the key date, whose reciprocal values determine the takt times. You define these rates for the line resources in the SAP APO, which were generated when the lines were transferred to the SAP APO.

The product-dependent rates that the system saves as a factor relative to the base rate. Takt-based scheduling multiplies this factor with the valid production rate of the period and in this way controls the production rate in scheduling. You define this rate in a capacity variant that you have created for the line resource.

Features

In takt-based scheduling, the system multiplies the number of takts of the longest path through the line with the takt time. The takt time results from the production rate, if you have entered a valid production rate for the current period. Otherwise the system uses the base rate of the line.

Since the system calculates the longest path through the line, possible feeder lines are also scheduled.

The system use the line resource to calculate the operating time of the line. It takes the shift model and break times into consideration. If you have grouped together several lines to form a line network, the system also considers different operating times of the individual lines.

You can use two procedures in takt-based scheduling:

If you adjust the speed of the production line to the operating level, you use the rate-dependent takt time .

If you leave the speed of the production line constant, you can use the rate-independent takt time .

Note that the rate of capacity utilization, which you can enter in the line resource, has a similar effect to the production rate. The system uses the production rate to determine a factor relative to the base rate, which it multiplies with the base rate in scheduling. The rate of capacity utilization has exactly the same function. If you enter a production rate and also change the rate of capacity utilization of the line, both these parameters have a multiplying effect.

If the base rate is 100pc/hr, the production rate is 80pc/hr, and the performance level is 80%, the system schedules with 64 pc/hr.

Example

The following example shows how lead time scheduling would produce a false result. Takt-based scheduling, on the other hand, which multiplies the takt time with the number of takts, produces a correct result.