Calculating the Statistical Range of Coverage (SAP Library - Material Requirements Planning (PP-MRP))

Calculating the Statistical Range of Coverage

Implementation Options

Calculating the range of coverage serves to determine a dynamic safety stock level based on current requirements. Statistical, in this context, means it is not the actual requirements that are taken into account, but the average daily requirements within a defined period that are calculated by the system.

During the planning run, the system recalculates the dynamic safety stock for each MRP element and this safety stock is then available for planning purposes.

The statistical range of coverage calculation usually refers to the concrete requirements of make-to-stock production. You can therefore only use this for requirements, which the system lists in the net or gross planning segments of the MRP list and the stock/requirements list.

Prerequisites

The system divides up the requirements relatively evenly, that is, there are not any great variations in the requirements within the periods based upon the calculation.

In Customizing for MRP, you have defined a range of coverage profile in the IMG activity Define range of coverage profile (Dynamic safety stock). There you have determined the parameters for calculating average daily requirements as well as minimum, maximum and target ranges of coverage for different time periods.

To do this, you start from MRP in the SAP Easy Access menu and choose Environment ® Current settings ® Define range of coverage profile (Dynamic safety stock). You do not therefore need any customizing authorization in order to maintain an appropriate profile.

You have assigned the range of coverage profile to the material in the material master (MRP 2 view).

Process Flow

The system calculates the average daily requirements using the parameters defined in the range of coverage profile (see Calculating the Average Daily Requirements).

The system reads the defined ranges of coverage in the range of coverage profile and calculates the minimum, maximum and target range of coverage (see Calculating the Minimum, Maximum and Target Stock Level and Values of the Statistical Range of Coverage Calculation). The target stock level represents the safety stock level.

The system checks for every MRP element whether the available quantity is below the minimum stock level. If stock falls below the minimum stock level due to a requirement, the system creates a procurement proposal and thus calculates the procurement quantity, so that the available quantity is replenished up to the target stock level (see Calculating the Dynamic Safety Stock).