A perspective of software trustworthiness based on distrustable factors

Software trustworthiness is one of most important measurements of software quality. Much effort has been spent in searching for methods of improving software trustworthiness. However, nowadays the concept and attributes of trustworthiness are still studied insufficiently; the researches in software trustworthiness have focused on satisfying the expectations of end users while ignored the importance of intermediate stages of software life cycle. This paper first reviews the history of trustworthiness and then explains briefly the differences between dependability and trustworthiness. We analyze the characteristics of software trustworthiness through software development life cycle, and define the software trustworthiness and software stage trustworthiness. We introduce the concept of distrustable factors to reveal why software defects could be there. We propose a formal software trustworthiness model to analyze further how distrustable factors impact the deliverables. Then, we use an example of common defects to show the identification of distrustable factors.