关键词: 软件度量, 功能规模度量, 功能点分析, IFPUG方法, 简化功能点

Abstract: Software scale measurement is an important basis for project management, especially in the early stage. IFPUG FPA（Function Point Analysis）, as a standard software scale measurement method, needs detailed information of software and has complicated computation, hence meets restrictions on the early stage of project application. This paper puts forward a simplified estimation method based on IPFUG FPA to solve the problem. Instead of making use of five objects in the standard method, the new method needs only three objects, including software transaction function, internal data functions and external data functions. Through fixing weighted factor for each object and giving functional point value and range, the method achieves software functional scale. It reduces the difficulty of usage and simplifies the estimation procedure, and the reliability is more than 60% through practical program validation.

Key words: software metrics, Functional Size Measurement （FSM）, Function Point Analysis （FPA）, IFPUG（International Function Point Users&rsquo, Group）, simplified function point