Scheduling and Capacity Requirements Calculation

Scheduling is an important tool for calculating capacity requirements. During scheduling, the system determines the start and finish dates for various order categories and writes capacity requirements records. The system carries out scheduling using task lists from various applications, for example:

So that capacity requirements can be determined you must specify formulas to calculate capacity requirements in work center and capacity maintenance.

Scheduling Levels

Scheduling and the calculation of capacity requirements can be carried out in different levels of detail. You can distinguish between the following levels of detail or scheduling levels.

For example, it may be sufficient for rough-cut planning to take the execution time of an operation into account and carry out scheduling and calculate capacity requirements at a rough-cut level. On the other hand, even at the rough-cut level, it can be useful to determine the capacity requirements in detail at the detailed level.

The capacity load of a production line in repetitive manufacturing is usually determined at production rate level. However, if there is a station within this production line that is also used for the work centers of production orders then it is sensible to carry out capacity planning at the detailed scheduling level for this station.

The following table shows the scheduling levels at which scheduling can be carried out in the various applications.

Scheduling levels in the various application areas

Application

Rough-cut scheduling

Production-rate scheduling

Detailed scheduling

SOP, LTP, MRP, MPS, SFC, REM

X

X

X

PM, PS, PP-PI

    

X

You can specify for each scheduling level the task list type to be used for scheduling in Customizing for capacity planning. You can do this for the various applications see also Parameters for scheduling and capacity planning). In this way you can carry out scheduling at different levels of detail depending on the needs of the business.

Generally, routings are used at the detailed scheduling level, rate routings at production rate scheduling level and rough-cut planning profiles at the rough-cut scheduling level. However, you can use a different task list type from usual for every scheduling level. Scheduling in plant maintenance generally takes place using the routing; a network is always scheduled using a standard network.

You can find more details on scheduling and capacity requirements calculations in the documentation for the specific application areas.

View of capacity requirements

You can create capacity requirements in various applications, that is, for the different scheduling levels for the various planning levels. Capacity requirements resulting from detailed scheduling, rate-based scheduling and rough-cut scheduling for a product at a particular time in an application exist in the system at the same time and can be viewed separately.

When you convert a planned order to a production order, the system reschedules the production order and deletes the planned order. In this case, the system transfers the capacity requirements for rough-cut and rate-based planning to the production order.

Manually created production orders are scheduled using rate-based scheduling or rough-cut scheduling if you have specified the following in Customizing where you specify the scheduling parameters for production orders for the order category:

Rate-based scheduling or rough-cut scheduling is carried out again if the quantities or the basic dates have changed in the production order.