A similar distinction is made between validation and verification, known as V&V in the testing trade. ISO/IEC 9126 distinguishes between a defect and a nonconformity, a defect being "The nonfulfilment of intended usage requirements", whereas a nonconformity is "The nonfulfilment of specified requirements".
TYPESY ISO SOFTWARE
This standard stems from the GE model for describing software quality, presented in 1977 by McCall et al., which is organized around three types of quality characteristic: Ideally, the internal quality determines the external quality and external quality determines quality in use. Quality-in-use metrics are only available when the final product is used in real conditions. Internal metrics are those which do not rely on software execution (static measure).Įxternal metrics are applicable to running software. This may be done, for example, by specifying target values for quality metrics which evaluates the degree of presence of quality attributes. On doing so, however, it leaves up to each organization the task of specifying precisely its own model. The standard provides a framework for organizations to define a quality model for a software product. As a result, the notion of user extends to operators as well as to programmers, which are users of components such as software libraries. Software product is defined in a broad sense: it encompasses executables, source code, architecture descriptions, and so on. Attributes are not defined in the standard, as they vary between different software products. An attribute is an entity which can be verified or measured in the software product. adaptability) is further divided into attributes. Portability - "A set of attributes that bear on the ability of software to be transferred from one environment to another."Įach quality sub-characteristic (e.g.Maintainability - "A set of attributes that bear on the effort needed to make specified modifications.".Efficiency - "A set of attributes that bear on the relationship between the level of performance of the software and the amount of resources used, under stated conditions.".Usability - "A set of attributes that bear on the effort needed for use, and on the individual assessment of such use, by a stated or implied set of users.".Reliability - "A set of attributes that bear on the capability of software to maintain its level of performance under stated conditions for a stated period of time.".The functions are those that satisfy stated or implied needs." Functionality - "A set of attributes that bear on the existence of a set of functions and their specified properties.The quality model presented in the first part of the standard, ISO/IEC 9126-1, Ĭlassifies software quality in a structured set of characteristics and sub-characteristics as follows:
0 kommentar(er)
