Show TOC

 Date Determination at Operation Level Locate this document in the navigation structure


With this function, the system determines the start and finish dates of operations while scheduling orders.

The lead time of an operation can be divided into the following time segments:

  • Queue time (operation float)

  • Setup time

  • Processing time

  • Teardown time

  • Wait time

The setup time, processing time and teardown time together make up the execution time of an operation.

The execution time, queue time and wait time together make up the lead time of an operation.

You can also define a move time . Move time is the time required to move a material from one work center to another. The move time always lies between two operations and is assigned to the preceding operation.

The queue time, wait time and move time together make up the interoperation time of an operation.

 ( )


How an operation is scheduled depends on whether it is marked for in-house processing or external processing in the Control Key .

Scheduling In-House Operations

Duration of Queue Time

You can define a queue time (normal, minimum) in both the work center and the operation. The system carries out scheduling using the queue time from the work center only if you have not maintained a queue time in the operation. The queue time is an additional means of neutralizing disturbances and delays for each operation (see queue time (earliest and latest dates in the operation) .

The queue time is defined in the routing operation and transferred to the production order. The queue time can be changed in the production order.

Duration of Execution

In the work center ( Scheduling tab page), you can specify different formulas for calculating the duration of the operation segments: Setup, processing and teardown. The system uses these Formulas to determine the execution time of an operation in the production order. You can insert the following parameters into the formulas:

  • Operation standard values

  • Performance efficiency rate, that is the percentual relationship between the defined target time and the actual time (defined per standard value).

  • Operation lot size

  • Base quantity to which the standard values refer

  • Total number of splits

  • Formula constants

  • User fields (tab page of the operation)

If you have not maintained standard values or a formula for one of these three operation segments, the system assumes that the duration of the corresponding segment is 0.

In the work center, you can maintain separate formulas for calculating durations and capacity requirements. The system can only determine the duration of individual operation segments if you have maintained the formulas on the Scheduling tab page of the work center.

Capacity Utilization Rate

The system takes breaks and organizational and/or technical disturbances into account by lengthening the duration of the operation segments accordingly Queue, Setup, Process and Teardown (see diagram) .

 ( )

Duration of Wait Time

The minimum wait time is defined in the routing.

Duration of Move Time

You can maintain a move time in the following places:

  • In the operation

  • With location groups in the move time matrix

On the Interoperation times screen in the operation, you can maintain a minimum and a standard move time. If reduction measures are carried out, the system schedules the operation using the minimum move time (see Reduction Measures ).

If you do not maintain any move times on the Interoperation times tab page, the system determines the move times using the location groups maintained in the move time matrix.

In the move time matrix , you can specify planned values for the move time within a location group or from one location group to another. For each entry, you can specify a minimum and a standard move time. If reduction measures are carried out, the system schedules the operation using the minimum move time (see Reduction Measures ).

Work centers that are close in proximity to each other can be grouped together in location groups . Location groups and move time matrices are maintained in Customizing (Customizing for Shop Floor Control by choosing   Operations   Scheduling   Define Move Time Matrix   ). You assign a work center to a location group on the scheduling screen of the work center.  

The move time matrix is maintained in customizing.


The dates of the operation segments are determined by distributing the duration of the operation segments, corresponding to the work time of the work centers, along the time axis (see diagram). In this process, the system also takes into account the time relationships between operations, that is, overlaps of operations and the position of float times that occur when you work with parallel sequences .

The work time of the work centers is either calculated from the standard available capacity (breaks are evenly distributed) or from the active version of the available capacity ( scheduling allowing for breaks ).

If times are at the start of a shift/end of shift or at midnight, the following rules apply:

  • Starting times are aligned with the start of the shift or 0:00.

  • Finish times are aligned to the end of the shift or 24:00.

  • If an operation with a duration of 0 is scheduled for one of these dates, the following special rules apply:

  • in forward scheduling, start and finish times are aligned with work finish or 24:00

  • in backward scheduling, start and finish times are aligned with work start or 0:00

This is necessary in order to avoid finish times preceding start times.

Scheduling Externally Processed Operations

In the Control Key you decide the data upon which scheduling is to be based for externally processed operations. You have the following options to choose from:

  • Scheduling using standard values

In this case, the operation dates are determined in exactly the same way as for in-house operations (see above).

  • Scheduling using the planned delivery time

In this case, operation dates are determined taking the following factors into account:

  • Planned delivery time and the Gregorian calendar

The system uses the planned delivery time of the operation as the basis for the duration (see General data screen, External processing section). This is distributed along the time axis using the Gregorian calendar.

The same rules apply here as for in-house operations (see above).