To be able to calculate operation dates, the system needs to be able to calculate a duration and an operating time per operation segment. For each scheduling run, the system places each operation segment on the time axis, taking into account the operating time defined for the operation segment in question. The result of this procedure is the individual operation dates.

The operating time specifies when work is to be carried out. The calendar used for scheduling distinguishes between workdays and non-working days. You can define an operating time in the system by specifying the start and end of shifts as well as the breaks for each workday.

The following rules apply:

• If the unit of the operation segment is smaller than the unit day, the operating time per workday applies

• If the unit of the individual operation segments is greater than or equal to the unit day, the operation segments are scheduled to the day on the basis of the calendar used for scheduling

The following operating times apply to the individual operation segments:

• For the operation segments wait, setup, processing and teardown, the operating times defined in the work center per day and the calendar specified in the work center or operation apply

The following applies for calculating the operating time per workday:

• In addition to the start and end of shift and the break times, the rate of capacity utilization for the work center is taken into account when calculating the operating time.

• The capacity utilization rate represents the ratio between the actual capacity of a machine and the theoretically available capacity. This value shows you if there are any technical and organizational malfunctions. The relevant capacity utilization rate for scheduling is defined when maintaining the capacity category, which is the basis for scheduling.

• The operating time of the work center is defined for the capacity category that is specified on the scheduling screen.

The following applies for selecting the valid calendar:

• The work center calendar has highest priority. If no calendar is maintained there, then the Gregorian calendar applies.

• The wait time is scheduled independently of the factory calendar, that is the wait time can be scheduled daily from 0.00 to 24.00.

• The operating time of the move time is determined via parameters specified in the move time matrix. In the move time matrix, you can enter in the Calendar field which of the following calendars determines the operating time:

• Calendar of the initial work center
• Calendar of the target work center
• Calendar of the move time matrix

• The delivery time is specified in days for operations processed externally. These operations are scheduled on the basis of the Gregorian calendar.

You can set the indicator Exact breaks (Customizing for Shop Floor Control by choosing Operations ® Scheduling ® Define Scheduling Parameters):

• If the indicator is set, the exact times of the breaks are taken into account For scheduling with breaks to occur, an active version of the available capacity must have been entered in the work center.

• If the indicator is not set, the system distributes the break time evenly over the day In this case, you may find that an operation date is scheduled within a break time

If no operating time is maintained for a time segment, the system calculates using an operating time from 0:00 to 24:00.