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# SAP PaPM: Sequence of Calculation functions use case

Let me share with you one of the possible ways to configure the Calculation function was used to compute the groups of indicators within the certain project application.

For more information about Calculation function see at SAP Help.

For indicator groups a sequence of calculation functions was created and configured in such way: results indicators of the previous function become input parameters for calculating indicators within the next function and can be recalculated by using additional parameters.

The next conditions were defined the splitting of calculation functions within the sequence:

1) The coherent interface of PaPM function provides business users ability to configure the calculation themselves. They recognize formulas according to methodology cases and can make changes without IT.

2) The splitting responsibility according to the methodology cases, calculation and verification of results between different departments must also be implemented in the system.

3) This approach allows the scaling of functionality in a short time. In fact, there were about 1000 methodology cases, and the distribution into groups had had made it possible to configure and test quickly.

To implement the requirements, the following actions were carried out at the design:

- Indicators were organized as a BW dimension with Indicators ID and Description.

To match the Indicator and the Calculation Rule the naming requirement have defined: The Calculation Rule is equal to a certain symbols of dimension’s ID with additional suffix. The suffix is used for navigating through the calculation function and defines the indicator’s relationship as an input parameter in the calculations. In case the indicator is an input parameter from the input form or from the previous calculation function, then it is marked with the suffix ‘R’ (you can look it through the screens bellow).

- The indicators were splatted into groups and ordered within them according to the calculation method.

Methods for calculating indicators are complex of mathematical formulas, which refer each others. Some of formulas were transformed and simplified during the ordering. For this purpose, binary matrices were constructed and transformed to lower triangular ones. (Triangular matrix guaranties direct calculation without cycles).

- For each group of indicators, a separate calculation functions (Stages) were configured.

As a result, the configuration looks like bellow:

As mentioned above, the calculation involves a large number of rules and stages. Hence, it was necessary to ensure auditability of the calculation, which means to answer: which input indicator value was, how it was recalculated, which stage changed value?

To provide auditability, the function configuration includes 2 analytics in addition to the principal formula definition: Stage marker and Calculation order per Stage, as you can see in the figure below:

These additional analytics allow you to trace the indicator’s value per Stage.

And as a Value Flow:

* don’t be confused by the meaning of Stage ‘#’ – this analytic stores reconciliation values.

As a result, the speed of calculating metrics was reduced by 15 times and improved the efficiency of business users.

Certainly, it was an interesting task that brought significant value for business and I hope my experience would be useful for you.