Comparing internal and external software quality measurements

Modern software development companies that have a quality assurance program use measurements and standards to improve product quality as perceived by the users of these products. However, during the entire software life cycle, except for the final customers, different types of 'users' also appear. This paper firstly shows the different views of software quality of these types of users. It also presents the internal and external measurement methods that we used in order to measure the users' opinion of software quality, the benefits and drawbacks of each method, as well as information concerning the techniques used to conduct internal and external measurements. Surveys and examples showing whether software metrics and external views of quality are correlated are also presented. The aim of this paper is to determine up to what point and in which cases can we rely on software metrics in order to define the users' perception of software quality.