Function Point and Function Point Analysis

Introduction

One of the most important thought that comes to the table of discussion while selling or buying software is "what is the real worth of the software ?" or "What should be the optimal cost of it ?". As software don't have a traditional measuring unit. The difference was previously only evaluated based on the user experience of how much time this software will require to make.

Explanation

To overcome these difficulties and to give a standardized view to the software a unit of software was derived know as Function Point.

The wikipedia defines function point as follows:

A Function Point is a unit of measurement to express the amount of business functionality an information system provides to a user.

To understand it better I would say that function point is to software as Celsius is to Temperature or KG is to weight or Meter is to length. It is simply a Unit of Measure for software.

Function points are an ISO recognized Software Metric to size an information system based on the functionality that is perceived by the user of the information system, independent of the technology used to implement the information system.

In summary, the function point technique provides an objective, comparative measure that assists in the evaluation, planning, management and control of software production.

This means that the size of the software can be measured in terms of function points. Now this is great as this will also allow us to come on the ground that we can charge a buyer of buy software based on the function points and there can be price fixed for each function point.

The concept of Function Point was originally defined by Allan Albrecht of IBM in 1977.

With FP (Function Point) came a standard methodology of determining the FP know as FPA (Function Point Analysis)

Function Point Analysis (FPA) is a sizing measure of clear business significance. First made public by Allan Albrecht of IBM in 1979, the FPA technique quantifies the functions contained within software in terms that are meaningful to the software users. The measure relates directly to the business requirements that the software is intended to address. It can therefore be readily applied across a wide range of development environments and throughout the life of a development project, from early requirements definition to full operational use. Other business measures, such as the productivity of the development process and the cost per unit to support the software, can also be readily derived.

The function point measure itself is derived in a number of stages. Using a standardized set of basic criteria, each of the business functions is a numeric index according to its type and complexity. These indices are totaled to give an initial measure of size which is then normalized by incorporating a number of factors relating to the software as a whole. The end result is a single number called the Function Point index which measures the size and complexity of the software product.

In summary, the function point technique provides an objective, comparative measure that assists in the evaluation, planning, management and control of software production.

Its worth mentioning that IFPUG (International Function Point User Group) is the architect and torch bearer for promoting the FPA methodology and effective management of Software Applications Development and maintenance through use of FPA.

Next Edition

Please check my next article here on detailed explanation of calculating Function Points.

References

www.ifpug.org, http://en.wikipedia.org/