What is Functional size?


Functional size is defined in ISO 14143-1:2007(E) as: "a size of the software derived by quantifying the Functional User Requirements (FUR)," where FUR is as "a sub-set of the User Requirements describing what the software shall do, in terms of tasks and services" [1].

Examples of FUR are:

  •    input of students data in a registration system;
  •    calculate the average mark of students in a course;
  •    list the students that are above the average.

More examples of FUR can be found in [1].