Function Point Analysis

programming (FPA) A standard metric for the relative size

and complexity of a software system, originally developed by

Alan Albrecht of IBM in the late 1970s.

Functon points (FPs) can be used to estimate the relative size

and complexity of software in the early stages of development

- analysis and design. The size is determined by identifying

the components of the system as seen by the end-user: the

inputs, outputs, inquiries, interfaces to other systems, and

logical internal files. The components are classified as

simple, average, or complex. All of these values are then

scored and the total is expressed in Unadjusted FPs (UFPs).

Complexity factors described by 14 general systems

characteristics, such as reusability, performance, and

complexity of processing can be used to weight the UFP.

Factors are also weighted on a scale of 0 - not present, 1 -

minor influence, to 5 - strong influence. The result of these

computations is a number that correlates to system size.

Although the FP metric doesn't correspond to any actual

physical attribute of a software system (such as lines ofcode or the number of subroutines) it is useful as a relative

measure for comparing projects, measuring productivity, and

estimating the amount a development effort and time needed for

a project.

See also International Function Point Users Group.

(1996-05-16)