An order or task list is scheduled to determine dates for all of its operations. In addition, capacity requirements are determined by scheduling.
Scheduling can be order-related or non order-related:
- Order-related scheduling is carried out for planned orders and work orders. In work orders, scheduling is always carried out using a routing. Planned orders can be scheduled using the in-house production time in a material master record and the routing. The determined dates are saved.
For additional information about order-related scheduling, refer to the R/3 Library PP Production Orders and PP Material Requirements Planning.
- Non order-related scheduling is carried out using routings. This type of scheduling can be used to calculate the in-house production time of a material and compare it to the lot size-independent in-house production time from the material master record. The lot size-independent in-house production time from the material master record can then be automatically or manually adjusted.
The control key of an operation influences scheduling in the following ways:
- If the control key of the operation specifies that the operation can be scheduled, the system calculates the duration and the dates of the operation segments.
- If the control key of the operation specifies that the operation cannot be scheduled, the system assigns a duration of zero to all operation segments.
- If an operation is externally processed and the Sched external op. indicator Fremdvorgang im Steuerschlüssel
- Has not been set, the system schedules the operation by using the planned delivery time on the external processing screen of the operation
- Has been set, the system uses the standard valus from the externally processed operartion to calculate the duration of the operation, as for an internally processed operation
Rules for Calculating Times
If times that are calculated in scheduling correspond to work start, work finish or midnight, the following rules apply:
- Start times are scheduled for work start or 0:00.
- Finish times are scheduled for work finish or 24:00.
- If an operation with a duration of zero is scheduled for one of these times, the following rules apply:
- For forward scheduling, the start and finish times are scheduled for work finish or 24:00.
- For backward scheduling, the start and finish times are scheduled for work start or 0:00.
This is necessary to make sure that the finish time is not before the start time.
The following sections describe the features in scheduling and the factors that are taken into account and influence the calculation of the dates:
Floats Before and After Production
Alignment Key in Parallel Sequences
Example: Calculating Operation Dates