theorycomputation-theoryfunction-points

How to calculate function points


This is a question about theoretical computing. I have came through a question like below;

Consider a project with the following functional units :

Assuming all complexity adjustment factors and weighing factors as average, the function points for the project will be;

The answer is 672. How is this calculated?


Solution

  • 1. Typical complexity averages are as follows:

    Table of function-points average

    AVERAGE complexity weights = {4, 5, 4, 10, 7} for the 5 complexities respectively.


    2. Typical Characteristic weights are as follows:

    Table of characteristics weights

    AVERAGE characteristic weight = 3.


    3. Function point = FP = UFP x VAF

    UFP = Sum of all the complexities i.e. the 5 parameters provided in the question,
    VAF = Value added Factor i.e. 0.65 + (0.01 * TDI),
    TDI = Total Degree of Influence of the 14 General System Characteristics.

    functional-points calculation

    Thus function points can be calculated as:

    = (200 + 200 + 140 + 60 + 28) x (0.65 + (0.01 x (14 x 3))
    = 628 x (0.65 + 0.42)
    = 628 x (1.07)
    = 672
    

    Thus the function points for the project will be 672.


    Checkout this article for a detailed walk-through into function-point calculations.