ISO/IEC 14143的本部分定义了功能尺寸测量（FSM）的基本概念，并描述了应用FSM方法的一般原则。ISO/IEC 14143的这一部分没有提供关于如何1）使用特定方法测量软件功能大小、2）使用从特定方法获得的结果、3）选择特定方法的详细规则。当确定软件尺寸测量方法是否为功能尺寸测量方法时，ISO/IEC 14143本部分中FSM的定义适用。它并不妨碍各种方法的发展，而是为评估特定方法是否符合FSM提供了依据。ISO/IEC 14143的本部分旨在供与软件的获取、开发、使用、支持、维护和审核相关的人员使用。

This part of ISO/IEC 14143 defines the fundamental concepts of Functional Size Measurement (FSM) and describes the general principles for applying an FSM method. This part of ISO/IEC 14143 does not provide detailed rules on how to 1) measure Functional Size of software using a particular method, 2) use the results obtained from a particular method, 3) select a particular method. The definition of FSM in this part of ISO/IEC 14143 is applicable when determining if a method for sizing software is a Functional Size Measurement Method. It does not prevent the development of various methods, but rather provides a basis for assessing whether a particular method conforms to FSM. This part of ISO/IEC 14143 is intended for use by those persons associated with the acquisition, development, use, support, maintenance and audit of software.