How to calculate function points

Question

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

Consider a project with the following functional units :

• Number of user inputs = 50
• Number of user outputs = 40
• Number of user enquiries = 35
• Number of user files = 06
• Number of external interfaces = 04

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?

Answer 1

1. Typical complexity averages are as follows:

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

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2. Typical Characteristic weights are as follows:

AVERAGE characteristic weight = 3.

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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.

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.

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