Context: Defects occurred in the SRS may cause problems in project due to implementation of poor requirements which require extra time, effort, resources and budget to complete it. Reading techniques i.e., checklist based reading (CBR) helps to guide reviewers in identifying defects in software requirement specification (SRS) during individual requirement inspections. Checklists contain potential defects/problems to look for, but often lack clear definitions with examples of the problem, and also their abstractions are different. Therefore, there is a need for identifying existing defects and classifiers and to create a consolidated version of taxonomy. Objectives: We developed taxonomy for requirement defects that are in requirement specifications and compared it with the checklist based approach. The main objective was to investigate and compare the effectiveness and efficiency of inspection techniques (checklist and taxonomy) with M.Sc. software engineering students and industry practitioners by performing a both controlled student and industry experiment. Methods: Literature review, controlled student experiment and controlled industry experiment were the research methods utilized to fulfill the objectives of this study. INSPEC and Google scholar database was used to find the articles from the literature. Controlled student experiment was conducted with the M.Sc. software engineering students and controlled industry experiment was performed with the industry practitioners to evaluate the effectiveness and efficiency of the two treatments that are checklist and taxonomy. Results: An extensive literature review helped us to identify several types of defects with their definitions and examples. In this study, we studied various defect classifiers, checklists, requirement defects and inspection techniques and then built taxonomy for requirement defects. We evaluated whether the taxonomy performed better with respect to checklist using controlled experiments with students and practitioners. Moreover, the results of student experiment (p= 0.90 for effectiveness and p=0.10 for efficiency) and practitioner experiment (p=1.0 for effectiveness and p=0.70 for efficiency) did not show significant values with respect to effectiveness and efficiency. But because of less number of practitioners it is not possible to apply a statistical test since we also have used standard formulas to calculate effectiveness and efficiency. 2 out of the 3 reviewers using taxonomy found more defect types compared to 3 reviewers using checklist. 10-15% more defects have been found by reviewers using taxonomy. 2 out of the 3 reviewers using taxonomy are more productive (measuring in hours) compared to reviewers of checklist. Although the results are quite better than the student experiment but it is hard to claim that reviewers using taxonomy are more effective and efficient than the reviewers using checklist because of less subjects in number. The results of the post experiment questionnaire revealed that the taxonomy is easy to use and easy to understand but hard to remember while inspecting SRS than the checklist technique. Conclusions: Previously researchers created taxonomies for their own purpose or on industry demand. These taxonomies lack clear and understandable definitions. To overcome this problem, we built taxonomy with requirement defects which consists of definitions and examples. No claims are made based on student experiment because of insignificant values with respect to effectiveness and efficiency. Although the controlled industry experiment results showed that taxonomy performed slightly better than the checklist in efficiency i.e., in defect detection rate and effectiveness i.e., number of defect found. From this we can conclude that taxonomy helps guiding the reviewers to indentify defects from SRS but not quite much so it is recommended to perform a further study with practitioners in a large scale for effective results. / skarimuddin@yahoo.com, hassanshah357@gmail.com

Defect prevention (DP) in early stages of software development life cycle (SDLC) is very cost effective than in later stages. The requirements elicitation and analysis & negotiation (E and A&N) phases in requirements engineering (RE) process are very critical and are major source of requirements defects. A poor E and A&N process may lead to a software requirements specifications (SRS) full of defects like missing, ambiguous, inconsistent, misunderstood, and incomplete requirements. If these defects are identified and fixed in later stages of SDLC then they could cause major rework by spending extra cost and effort. Organizations are spending about half of their total project budget on avoidable rework and majority of defects originate from RE activities. This study is an attempt to prevent requirements level defects from penetrates into later stages of SDLC. For this purpose empirical and literature studies are presented in this thesis. The empirical study is carried out with the help of six companies from Pakistan & Sweden by conducting interviews and literature study is done by using literature reviews. This study explores the most common requirements defect types, their reasons, severity level of defects (i.e. major or minor), DP techniques (DPTs) & methods, defect identification techniques that have been using in software development industry and problems in these DPTs. This study also describes possible major differences between Swedish and Pakistani software companies in terms of defect types and rate of defects originating from E and A&N phases. On the bases of study results, some solutions have been proposed to prevent requirements defects during the RE process. In this way we can minimize defects originating from E and A&N phases of RE in the bespoke requirements engineering (BESRE).

Developing software that meets the customers’ requirements, expectations, and quality standards is a challenging task for all software organizations. As modern software becomes more and more complex, so do the defects of the software. The aim of this study was to develop a simplified and consistent defect taxonomy that could be executable and usable for smaller enterprises or organizations that want to implement a simplified taxonomy. The aim of this study was also to find characteristic defects that exist in Small- and Medium-sized Enterprises (SMEs) by using the taxonomy. A manual defect classification was done on bug reports collected from three organizations with the same company size as SMEs. An agreement analysis was also conducted in this study to investigate the consistency of the taxonomy. This was done by letting different people classify a subset of the bug reports collected for this study using the proposed taxonomy. Furthermore, in this study, I also investigated how executable and usable the taxonomy would be for smaller enterprises. This was done through four interviews and a survey with seven respondents. The result of the defect classification indicates that Program anomaly (58%), GUI (17%) and Configuration (13%) are three of the most common defect types that exist in SMEs. The result of the defect classification indicates that SMEs have a problem with defects breaking features that worked correctly before, where 19% of all bug reports used in this study were classified as Regression. The survey result indicates that taxonomy is easy to use. However, the result of the different classifications showed that the use of the taxonomy is not consistent between different classifiers. The results of the interviews and the survey indicate that the taxonomy would be executable for smaller enterprises. However, to also be fully usable, the proposed taxonomy needs to be adapted to the particular enterprise, and requires the right competence to propose appropriate measures for the particular enterprise. / Att utveckla mjukvara som möter kundernas krav, förväntningar och som håller en hög kvalité är en utmanande uppgift som alla företag står inför. Den moderna mjukvaran blir allt mer komplex, vilket i sin tur även bidrar till fler och mer komplexa mjukvarufel. Den här studien har som mål att skapa en ny förenklad och konsekvent defekttaxonomi som kan vara genomförbar och användbar för mindre företag och organisationer som vill använda sig av en enklare taxonomi. Målet med det här examensarbetet är också att kartlägga karaktäristiska mjukvarufel i små och medelstora företag med hjälp av den nyutvecklade taxonomin. För att lyckas med detta klassificerades felrapporter från tre organisationer som är av samma storlek som små och medelstora företag. Den här studien analyserade även hur konsekvent taxonomin är genom att låta olika människor klassificera en delmängd av studiens felrapporter. Den här studien undersöker även hur genomförbar och användbar defekttaxonomin är för mindre företag. Detta genomfördes genom fyra intervjuer och en enkätundersökning med sju respondenter. Resultatet av den här studien indikerar att små och medelstora företag främst har problem med mjukvarufel som ger upphov till oväntat och oönskat beteende kopplat till mjukvarans funktionalitet (58%). Den här studien indikerar även att gränssnittsdefekter (17%) och konfigureingsproblem (13%) också är vanliga mjukvarufel inom dessa organisationer. Den här studien har även uppmärksammat att mindre företag kan ha problem med mjukvarufel som tar sönder funktionalitet som fungerat korrekt tidigare, även kallad regressioner, där 19% av alla felrapporter blev klassificerade som det. Resultatet av enkätundersökningen indikerar att taxonomin är enkel att använda. Å andra sidan, de olika klassifikationerna visade att användningen av taxonomin inte var konsekvent. Resultatet av intervjuerna och enkätundersökningen indikerar att taxonomin är genomförbar för mindre företag. Å andra sidan, för att defekttaxonomin ska vara användbar behöver den anpassas efter det särskilda företaget. Den kräver även den rätta kompetensen för att ta fram lämpliga åtgärden för det särskilda företaget.