Function Points

Gaurav Taneja — Fri, 04 Aug 2006 10:10:00 GMT

Function Point Analysis is an objective and structured technique to measure software size by quantifying its functionality provided to the user, based on the requirements and logical design. This technique breaks the system into smaller components so they can be better understood and analyzed. Function Point count can be applied to Development projects, Enhancement projects, and existing applications as well. There are 5 major components of Function Point Analysis which capture the functionality of the application. These are: External Inputs (EIs), External Outputs (EOs), External Inquiries (EQs), Internal Logical Files (ILFs) and External Interface Files (EIFs). First three are treated as Transactional Function Types and last two are called Data Function Types. Function Point Analysis consists of performing the following steps:

Determine the type of Function Point count
Determine the application boundary
Identify and rate transactional function types to calculate their contribution to the Unadjusted Function Point count (UFP)
Identify and rate the data function types to calculate their contribution to the UFP
Determine the Value Adjustment Factor (VAF) by using General System Characteristics (GSCs)
Finally, calculate the adjusted Function Point count

Software Matrix

Function Points