Service order Scheduling

Work Center Capacity

The duration of an operation is depending on the amount of work that was planned and, on the number, and capacity of the assigned resource.

The amount of work and the number of resources are two figures that are entered directly on operation level:

For the further scheduling, some more “capacity details” are needed. They are taken from the assigned work center.

According to that, a work center is a prerequisite for the scheduling of the operation. Within the work center the capacity details can be found on the “capacities” tab:

Regarding standard scheduling of a work order operation, the start and finish date as well as the length of the break will have a an impact.
For example if a 4 hours work will be planned to start at 07:00 oclock, the scheduled finish would be 11:00 oclock (without break).
But if the scheduled start time will be e.g. 16:00 oclock, the end date and time will be one day later at 10:30 oclock, because the standard scheduling will automatically consider the end of the shift.
If there is a given length of the break, standard scheduling will also consider the break. If we use the capacity details as shown above, four hours work, started at 16:00 oclock will have a scheduled finish by the next day at 10:45 oclock.

Operation Details

For the scheduling of an operation, the “duration” is required. In standard SAP the duration will be calculated by the “work”, divided by the number of capacities.

With the “calculation-key” it can be selected whether the work or the duration will be calculated. Once the duration has been defined, the capacity details of the work center and the overall scheduling parameter from the order header will be taken into consideration. Most common scheduling parameter is “forward scheduling”. In this case the system will use the start of the todays shift as a starting date and time and will calculate the earliest finish date:

In this example the work center of the operation has a start time of 07:00 o`clock. The operating time for one day is 9 hours. The break has ½ hour. The overall duration of the operation will be = 2 hours + ½ hour x 2/9 = 2 + 6 2/3. If the start time is 07:00, the scheduled end will be 09:06:40.

If the scheduling type of the work order header will change to “Forward in Time” the “time” will be added to the basic start date on header level.

In this case the operation scheduling will take the start date from the order header instead of the start of the shift from the work center:

If there is more than one operation, the standard relationship between them will be “finish-start”. For example if there is a second operation, the scheduled start will be the scheduled end of the first operation:

Order Header

There are basically two fundamental settings, that will have an impact on the scheduling. One setting is the scheduling type. The scheduling type can be defaulted by order type. In SAP standard usually the “forward” scheduling is the default:

As mentioned in the chapter above, there is also the possibility to change to “forwards in time”:

Using the scheduling type “forward in time” will not only show an additional field for the time. In addition to that, this scheduling type will also influence the earliest start time.

When using the “forward” scheduling, the scheduled start time can be in the “past”, because the start time will be the start of the shift (and depending on when exactly you do the scheduling, this might be already in the past).

But when using the “forward in time” scheduling, the system will consider the date and time when executing the scheduling. That very moment will be the earliest start date and time of the order and the (first) operation.

SAP Customizing

Path: SPRO --> Plant Maintenance and Customer Service --> Maintenance and Service Processing --> Maintenance and Service Orders --> Scheduling

Another fundamental setting of work order scheduling is how the basic end and basic start will be adjusted. The standard is usually “Adjust basic dates, adjust dep. Reqmts to operation date”:

This setting will be done per maintenance planning plant and order type.

For standard (preventive) maintenance scheduling the forward scheduling and the adjustment of the basic start and end date is quite sufficient. But especially when working on contract and service level based activities, it might be necessary to differentiate between the scheduled work duration and the overall time frame that is given, until the execution becomes due. A possible solution to cover such a scenario could be, to decouple the scheduling of the operation from the adjustment of the basic dates:

With this setting the basic dates of the order header could represent the time frame, given by the contract respectively the service level. The scheduling details of the operations would determine the duration of the task(s), that have to be done.

Connector Customizing

As shown in the chapters above, there is a variety of settings to influence the scheduling on header and on operation level.

When sending such an order to FSM, there are some connector settings to determine, which dates (header or operation) will be used within the service call and/or the activity.

When releasing a service order, the order will become the service call and the operation(s) will become the activitie(s).

Within the service call type definition (/PACG/ECM_SCTD) the basic settings are done per company and order type.

This includes the settings for the scheduled start and finish dates as well as the “due date” (date until the order must be executed). The standard settings are usually as follows:

Due to the settings of the connector, start and end date of the service order will become start and end date of the service call. The end date of the service order will also become the due date of the service call. The scheduled start and finish of a operation will become the planned start and end date of the activity.