Writing a Key Figure Calculation

Once you have created a key figure, you can add calculations to it. Note the following modeling requirements:

• Any key figures that an end user is able to query from the UI must have a calculation at REQUEST level.

• A calculation at REQUEST level either must be an aggregation, or must have inputs from REQUEST level only.

• You can define calculations that aggregate the key figure data from a lower base planning level using an operator, such as SUM, MIN, or MAX.

• You can also define calculations across key figures, for example, KF1 plus KF2.

• A key figure referenced in a calculation must be specified as an input key figure for the calculation.

• Calculation inputs can be marked as stored or calculated. The calculation chain for every key figure must result in a stored key figure. For example, KF1@PL1 = KF2@PL1 plus KF3@PL1, key figure 2 (KF2) is a stored input key figure, and key figure 3 (KF3) is a calculated input key figure. The calculated chain for key figure 3 (KF3) must finish with a stored key figure (such as KF3@PL1 = SUM(KF4@PL2), where KF4@PL2 is a stored key figure.

Any key figure not marked as stored forces the system to locate a calculation to determine the values of the key figure for the calculation. In this way, calculations are linked together.

A complete list of requirements is listed in the Model Configuration Guide ＞＞ Modeling Requirements (Checks and Errors).

As previously mentioned, the request level is at the top of the key figure model, and at the bottom are datasources - stored inputs into the calculations.

The calculations defined in the Configuration app are translated into a calculation graph, which consists of different types of nodes and arcs.

The nodes of the calculation graph can have a colored background:

• No background: calculated node
• Green background: data source node (stored key figure values)
• Purple background: calculation in focus

The arcs of the calculation graph have, for example, one of the following colors, depending on the type of the node that the arc arrow points to:

• Light blue: Aggregation
• Medium blue: Simplified key figure calculations
  Note

  Later in the course, we will be working with some of these calculations.

• Orange: Inner join

The Key Figure Calculations app allows for the visualization of calculation graphs, root attributes, filter blocks, and where-used graphs.

Calculation chains can get quite complex, depending on the requirements. If the chain grows to 15-20 levels deep, there will likely be impacts on performance (including performance in the Excel UI), and it will be very challenging to find and correct errors.

It is a good practice to check the calculation chain and make decisions about breaking the calculations or attempting simplification.

You can use the Simulate Key Figure Calculations app to simulate and validate changes made to the calculation definitions of key figures without activating the planning area first.

The use case can be for working in a bigger team, where you do not need to wait for other configurators to activate the model if you want to check the performance of the configuration element you were working on.

Using the app, you can create and run simulations to check the correctness of each calculation step in the graph, from the level of stored input to calculations at REQUEST level, including interim calculation steps. The simulation details will render in table form and can be exported to Microsoft Excel.

To run a simulation, choose Create, select the planning area, the planning view template or favorite, the worksheet, and the key figure for which you want to run a simulation. You can simulate your user or another user. If you simulate another (business) user, planning view templates and favorites are filtered based on the permission filters of the business user when running the simulation. You can also give a name to the simulation.

To make the simulation more specific, you can define the following settings as well:

• The time period from which you want to read stored input
• Planning filter for attributes
• Scope of the simulation: you can run it for the complete graph or selected nodes only
• Number of days for which you want to store the simulation in the system

SAP Integrated Business Planning for Supply Chain usually works with huge data volumes. It is not uncommon, for example, to see master data types that have several million data records. To manage performance, queries are typically filtered.

You can use filters in the SAP Integrated Business Planning, add-in for Microsoft Excel (attribute-based or value-based filters) or in the Planning Filters app.

When filters are used, all attributes are filtered as early in the calculation chain as possible, ideally on the level of stored key figures.

Some modeling techniques prevent filtering on the level of stored key figures by imposing filter blocks for certain attributes in certain calculations. A filter block is required for these calculations so that they provide correct results at time attribute transformation, at master data transformation and at cross-period calculations.

As explained in the previous section, filter blocks are displayed in the calculation graphs, allowing you to get a better understanding of how to filter more effectively and how to improve the performance of queries.

Select a planning area and a key figure, then choose Go to display the calculation graph.

Choose the Filter Blocks → Show All Attributes tab to display attributes where filter blocks are raised, as well as attributes where filtering is possible.

To learn about the details and causes of the filter blocks, select an attribute for which a filter block exists or display the node info.