Excerpts from the Introduction:

Systems continue to grow in size and complexity, becoming increasingly difficult to understand. As improvements in coding tools allow software developers to produce larger amounts of software to meet ever-expanding user requirements, a method to understand and communicate size must be used. A structured technique of problem solving, function point analysis is a method to break systems into smaller components, so they can be better understood and analyzed. This book describes function point analysis and industry trends using function points.

Human beings solve problems by breaking them into smaller, understandable pieces. Problems that may initially appear to be difficult are found to be simple when dissected into their components, or classes. When the objects to be classified are the contents of software systems, a set of definitions and rules, or a scheme of classification, must be used to place these objects into their appropriate categories. Function point analysis is one such technique: FPA is a method to break systems into smaller components, so they can be better understood and analyzed. It also provides a structured technique for problem solving. Function Point Analysis is a structured method to perform functional decomposition of a software application.

Function points are a unit measure for software much like an hour is to measuring time, miles are to measuring distance or Celsius is to measuring temperature. Function Points are interval measures much like other measures such as kilometers, Fahrenheit, hours, so on and so forth.

Function Points measure software by quantifying its functionality provided to the user based primarily on the logical design. Frequently the term end user or user is used without specifying what is meant. In this case, the user is a sophisticated user. Someone that would understand the system from a functional perspective --- more than likely someone that would provide requirements or does acceptance testing.

There are a variety of different methods used to count function point, but this book is based upon those rules developed by the Alan Albrecht and later revised by the International Function Point User Group (IFPUG). The IFPUG rules have much to be desired, so this book attempts to fill in gaps not defined by IFPUG.