 ## Example of Disaggregation and Rounding This example shows how a key figure is disaggregated under the following conditions:

·        The time characteristics in the planning area are month and week.

·        The planning area contains three characteristics: SKU (plant/material), sales organization, and ship from.

·        The calculation type is Pro rata.

·        No proportional factors exist.

·        Demand plans are created at the SKU level.

·        Planning is done on a monthly basis; that is, the time buckets profile attached to the planning book contains months only.

The system saves the data in technical periods. In a week containing a transition from one month to the next, there are two technical periods. In this way, the system distinguishes between the data belonging to one month and the next.

The following figure shows the plannable characteristic value combinations in the planning area:

You select one SKU (plant/material) in a new demand planning (DP) version. These five characteristic value combinations exist for the SKU: P1 L1, P2 L1, P3 L1, P4 L2, and P5 L2. You enter 100 pieces as the demand quantity in the month of May (month five). You save the data. The system first performs time-based disaggregation; in other words, it first disaggregates the 100 pieces of the SKU level into technical periods based on the number of workdays in each period. In this example, no factory calendar has been defined in the planning area, so there are seven workdays in each week. The month of May has 31 workdays. The calculation is as follows:

 Technical Period Number of Days in Technical Period Calculation Result Brought Forward 5/1-2 2 100 * 2/31 = 6.4516 6 + 0.4516 5/3-9 7 100 * 7/31 = 22.5806 23 ‑ 0.4194 5/10-16 7 100 * 7/31 = 22.5806 22 ‑ 0.4194 5/17-23 7 100 * 7/31 = 22.5806 23 ‑ 0.4194 5/24-30 7 100 * 7/31 = 22.5806 22 ‑ 0.4194 5/31 1 100 * 1/31 =   3.2258 3 + 0.2258 Total: 101 ‑ 1

The system now distributes the rounding difference -1 – which it collected previously over all periods – over all periods again:

 Technical Period Number of Days in Technical Period Calculation Result Brought Forward 5/1-2 2 ‑1 * 2/31 = -0.0645 0 ‑ 0.0645 5/3-9 7 ‑1 * 7/31 = -0.2258 0 ‑ 0.2903 5/10-16 7 ‑1 * 7/31 = -0.2258 0 ‑ 0.5161 5/17-23 7 ‑1 * 7/31 = -0.2258 0 ‑ 0.7419 5/24-30 7 ‑1 * 7/31 = -0.2258 0 ‑ 0.9677 5/31 1 ‑1 * 1/31 = -0.0323 -1 0 Total: ‑ 1 0

The result is as follows: The system assigns six pieces to the technical period 5/1-2 (two workdays). The system assigns 23 pieces to the technical periods 5/3-9, 5/10-16, 5/17-23, and 5/24-30 (seven workdays in each case) and assigns two pieces to the technical period 5/31 (one workday).

The system then performs disaggregation on a structural basis. This means that the system uses the calculation type; in this case, Pro Rata. The system disaggregates the values of the technical periods for the five characteristic value combinations to which this SKU belongs. Since no data has yet been created in the planning area and no proportional factors exist, the key figure values are distributed equally according to the defined calculation type. The rounding logic is the same as described above.

As an example, the 23 pieces, which are to be distributed in several technical periods (5/3-9, 5/10-16, 5/17-23, and 5/24-30), are calculated below for the five characteristic value combinations:

 Characteristic Value Combination Calculation Result Remainder P1 L1 23 * 1/5 = 4.6 5 -0.4 P2 L1 23 * 1/5 = 4.6 5 -0.4 P3 L1 23 * 1/5 = 4.6 5 -0.4 P4 L2 23 * 1/5 = 4.6 5 -0.4 P5 L2 23 * 1/5 = 4.6 5 -0.4 Total: 25 -2

The remainder -2 is distributed to the five characteristic value combinations:

 Characteristic Value Combination Calculation Result Remainder P1 L1 -0.2 * 1/5 = -0.4 0 -0.4 P2 L1 -0.2 * 1/5 = -0.4 0 -0.8 P3 L1 -0.2 * 1/5 = -0.4 -1 -0.2 P4 L2 -0.2 * 1/5 = -0.4 0 -0.6 P5 L2 -0.2 * 1/5 = -0.4 -1 0

The following table shows which of the five characteristic combinations the system assigns how many pieces:

 Characteristic Value Combination Result P1 L1 5 P2 L1 5 P3 L1 4 P4 L2 5 P5 L2 4

This means that each characteristic combination is assigned the relevant proportion from the table for each technical period for which the system can distribute 23 pieces.

The system performs this calculation accordingly for the periods 5/3-9 and 5/31. In the period 5/3-9, six pieces are distributed to the five characteristic combinations, and in period 5/31, two pieces are distributed to the five characteristic combinations.

The results are displayed schematically in the following figure: When you return to interactive planning, the system aggregates the data in the technical periods and shows you the following data for the month of May:  