Factors Influencing Scheduling 

Work Centers

You can enter a work center in internal and external activities and in relationships. In the work center, the following information is important for scheduling:

·        Formulas for calculating the duration of activities

·        Factory calendar and operating time per workday

Duration of activities

For internal activities and general costs activities, the system schedules using the normal duration you entered in the activity. If you entered a formula for the calculation of other types of internal processing in the work center, the system uses this formula to calculate the duration.

For external activities, the system schedules using  the number of delivery days you entered in the activity.

For general costs activities, the system schedules using the duration you entered for the activity.

The duration of an internally processed activity can be extended in scheduling if you have set the indicator Flex. duration on the detail screen. This may be the case, for example, if an activity has a free float.

If, according to the control key, the activity is not to be scheduled, the system assumes it has no duration.

Time interval of relationships

Scheduling interprets the time interval of the relationships as a minimum time interval. The system can increase the time interval during scheduling, but it cannot reduce it.

Operating Time

The operating time is the time at which work is carried out. In Customizing for the SAP system you specify working days  and public holidays in the factory calendar.

You can define the operating time at the work center per workday. You do this in the capacity category on the scheduling screen of the work center. Enter the following data:

·        Work start and finish

·        Break times

·        Rate of capacity utilization

Since the system distributes break times entered in the work center uniformly over the day in scheduling, scheduled start and finish times can lie within a break period.

If you set the Exact break times indicator, the system takes breaks into consideration when scheduling.

The following rules apply to network scheduling:

·        If you specify a unit that is smaller than "day" for the duration or the time interval, the system schedules using the operating time you have entered in the work center.

·        If you specify a unit that is greater than or equal to "day" for the duration or the time interval, the system schedules precisely to the day, using the calendar you entered as a basis.

Factory calendar

 

Scheduling uses...	if you...
the factory calendar in the work center	have entered a calendar in the work center.
the factory calendar in the activity or relationship	have not entered a calendar in the work center. you have not entered a calendar in the activity or for the relationship
the factory calendar for the plant	have not entered a calendar in the work center or activity

 

The system uses the Gregorian calendar when scheduling externally processed activities.

If you want to use the Gregorian calendar when scheduling internally processed activities, you must define a factory calendar that mirrors the Gregorian calendar.