Reliability Analysis and Management during Software Testing and Debugging

• Main Authors: Chu-Ti Lin, 林楚迪
• Other Authors: Chin-Yu Huang
• Format: Others
• Language: en_US
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/18584397497746310724

博士 === 國立清華大學 === 資訊工程學系 === 97 === Software reliability measurement plays a very important role in developing a robust and high quality software product. Over the past 30 years, many software reliability growth models (SRGMs) have been proposed for estimation of reliability growth of products during software development processes. Usually it is assumed that detected faults are immediately corrected when mathematical models are developed. This assumption may not be realistic in practice since the time to remove a detected fault depends on the skill and experience of personnel, the size of debugging team, and so on. Besides, during software testing, practical experiences show that mutually independent faults can be directly detected and removed, but mutually dependent faults can be removed if and only if the leading faults have been removed. Thus, the dependent faults may not be immediately removed and the fault removal process lags behind the fault detection process (FDP). In this dissertation, we will discuss the software fault dependency and study how to incorporate both fault dependency and debugging time lag into software reliability modeling. We also noticed that most SRGMs do not take into account possible changes of testing-effort (TE) consumption rates. However, in some cases, the policies of testing-resource allocation could be changed or adjusted. Thus, we will incorporate the concept of multiple change-points (CPs) into Weibull-type testing-effort functions (TEFs). Based on the proposed SRGMs, constructive rules are developed for determining optimal software release times (OSRTs) in terms of cost-reliability criterion. The main purpose is to minimize the cost of software development when a desired reliability objective is given. In addition to SRGM, the attractive rate-based simulation approaches have been proposed to describe the fault detection and correction processes during software testing phase. Thus far, it appears that most existing simulation approaches do not take into account the number of available debuggers. In practice, the number of debuggers will be carefully controlled. If all debuggers are busy, newly detected faults may have to wait (for a long time to be corrected and removed). Therefore, in this dissertation, we will apply the queueing theory to describe and explain possible debugging behavior. Two simulation procedures are developed based on G/G/∞ and G/G/m queueing models, respectively. The analysis through the proposed framework may greatly help project managers to assess the appropriate staffing level for the debugging team from the standpoint of performance and cost-effectiveness.