“Derived Fields” are variables that do not originally exist within a data source but are instead constructed using one or more existing fields from various data sources. Within procedures, the configuration window offers a “Derived Field” button, which facilitates the creation of variables for diverse purposes, including querying, segmenting, sorting, calculating, or generating output for a table.

If you desire a Derived Field to be accessible in processes, it can be enabled using the “Make” option during its creation. These Derived Fields, available within a process, can be located within the “Derived fields” folder. It’s important to note that these Derived Fields are exclusively accessible within the process in which they were generated. In the absence of any derived fields within a process, the “Derived fields” folder will not appear in the list.

For situations requiring the use of a derived field in subsequent processes or across various flowcharts, you have the option of storing its expression in the “Stored derived fields” list, making it accessible for all processes and flowcharts.

Furthermore, aside from creating individual Derived Fields, there exists the possibility to create nested Derived Fields. This approach permits the definition of variables within a Derived Field, facilitating the execution of all calculations within that same derived field, thus negating the need for multiple derived fields. To illustrate this concept further, consider a scenario where a Derived Field needs to calculate a single value based on previous calculations.

Traditionally, multiple Derived Fields would be created sequentially, followed by their utilization in the final Derived Field. However, a more efficient approach is available. By creating variables within the Derived Field, each calculation can be carried out individually and then incorporated into the final Derived Field.

 This approach is best illustrated through a concrete example: