Identifying the Basic Principles and Tools of Capacity Planning

The figure above describes the basic principles of SAP S/4HANA Capacity Planning:

• The master data of the work centers play a central role in capacity planning. In the work centers, the respective available capacities and formulas for calculating the capacity requirements of operations are defined. Work centers are assigned to the operations of routings.
• Planned orders or production orders are created on the basis of routings. Based on the work center formulas, lead time scheduling takes place for the orders and capacity requirements are created for their operations.
• The operations are scheduled infinitely, meaning that, although the non-working times of the work centers are taken into account when the system calculates processing date and time, the system assumes that the required capacity is always available when needed. Due to the fact that the capacity requirements of other orders are ignored in this approach, the assumption of infinite availability of capacities can lead to capacity overloads.
• In such situations, various tools are available for capacity evaluation and capacity leveling: In capacity evaluation, the available capacities of work centers are compared to the capacity requirements of operations. In capacity leveling, operations previously scheduled with infinite resource capacity are now scheduled finitely by allotting the respective operation to a time slot in which the required resource is not occupied. Following this approach, it is guaranteed that the operation can be executed on the requested resource at the planned time.

The figure above lists the capacity planning tools in SAP S/4HANA. For capacity evaluation, the following apps and evaluation reports are available enabling you to analyze a capacity situation:

• The Manage Work Center Capacity app provides a user-friendly interface in which the capacity load of work centers is displayed clearly and concisely, and which can be easily adjusted to individual questions and requirements.
• The Capacity Scheduling Board is a tool to analyze the schedule of operations and to dispatch, reschedule, or deallocate individual bottleneck operations on pacemaker work centers in a graphical chart.
• Various Capacity Evaluation Reports provide further options for flexibly analyzing the capacity situation of work centers.

For capacity leveling, you can use the following apps and planning tables:

• The Capacity Scheduling Table is a straightforward tool for the capacity leveling of planned, production and process orders. It provides a user-friendly interface that allows you to dispatch and deallocate bottleneck operations of orders transparently and easily.
• The Tabular Planning Table gives you a period-oriented, aggregate information on available capacities, capacity requirements, and capacity loads. In the tabular planning table, the capacity requirements of operations are dispatched to periods with free capacity. However, you cannot create a specific sequence for the dispatched operations within a period.
• The Graphical Planning Table enables you to carry out detailed planning of capacity requirements continuously over time. The requirements of operations are dispatched to individual capacities at exact times and in the sequence in which they are processed.

The following figure shows an example of capacity evaluation with the Manage Work Center Capacity app:

The overview screen of the Manage Work Center Capacity app displays a list of selected work center capacities. You obtain aggregated information on the capacity load within a selected evaluation horizon. Various filters and display options are available: You can, for example, display the maximum load, the time of the first overload, the backlog of overdue orders, and the total capacity requirements. Furthermore, the utilization can be displayed in a bar chart. The periods of normal load, critical load and overload are displayed in different colors (green, yellow, and red, respectively). The limits for the various load criteria can be set individually.

In the following figure, we show the capacity planning table and how an operation is dispatched to a work center:

The graphical capacity planning table consists of charts in which the working (white background) and non-working (gray background) times of work centers and the duration of operations (red bars) are displayed on a common time axis (yellow bars in the charts top section). Each chart has a title bar and consists of a table section (left) and a diagram section (right). The table section contains information for identifying and describing the operations or work centers displayed in the diagram section. In the figure above, the upper chart shows the selected work centers (T-BC300, T-BC400, and T-BC500) and the operations dispatched to them. The operations are displayed as bars. The darker time periods are the non-working times. The lower chart contains the pool of operations that have not yet been dispatched.

To dispatch an operation, you must first select it in the lower section (blue bar in the screenshot). Then you execute the dispatch function. Depending on the planning strategy set in the planning table, the system then searches for a free capacity in the work center chart and dispatches the operation.

In our example, in a first step, operation 0030 of order 220 was selected in the orders (pool) chart. Then the dispatch function was executed. At the initially scheduled time, an operation of order 214 was already dispatched. Therefore, in accordance with the planning strategy, the operation was finitely scheduled in the forward direction and dispatched after the operation of order 214.

As a result of dispatching, corresponding data is updated in the dispatched planned order or production order. If the operation of a planned order is dispatched, the Capacity Dispatched indicator is set in the planned order. If the operation of a production order is dispatched, the DSPT Dispatched status is set for the operation. In both cases, the dispatched operation cannot be rescheduled using lead time scheduling or infinite scheduling. Rescheduling of dispatched operations is only possible using finite scheduling in a planning board.