Managing Quality Requirements in Requirements Engineering Process : A survey

Abstract: Context. Requirements play vital role in building the software application.These requirements are of two types: Functional requirements andNon-functional requirements (or quality requirements). Many of the organizationsconsider only functional requirements during the early stages ofdevelopment cycle. Poor management of the non-functional requirementsmay affect factors such as success rate, project cost and standards of thebuilding product. So it is important to manage the quality requirements inthe right phase at the right time. Our thesis mainly concentrates on fivequality aspects of Requirements Engineering Process. The quality aspectsElicitation, Quality Requirements Metrics, Dependencies, Cost Estimationand Prioritization.We have concentrated on whether there are any changesin the focus on the quality requirements depending on the quality aspectsof requirement engineering process and in identifying which quality requirementis analysed at each of the five quality aspects depending on the functionalrequirements. And we also tried to identify the challenges faced bythe organizations due to handling of quality requirements at each of the fivequality aspects of the requirement engineering process in order to provideuseful information to the further studies to this problem. Objectives. In this thesis, we investigated how the quality requirementsare handled and managed in the 5 quality aspects of requirements engineeringprocess. The main objectives in this thesis are: To identify if the focus on quality requirements change with respect to tothe quality aspects of RE process. To identify a correlation between focusing on certain functional requirementand the resulting type of quality requirement i.e.; impact onquality requirements based on selected functional requirement. To identify the challenges faced by the organizations when focusing onthe quality requirements in each of quality aspects mentioned earlier. Methods. In this thesis study we first conducted a Systematic LiteratureReview (SLR) through Snowballing process to identify available literatureabout functional and non-functional requirements. Later Narrative analysiswas used to analyse the SLR results. Further an industrial survey wasconducted. Statistical analysis was performed, chi-square test of significancewas used to analyse the results. Results. The results for the research questions of this thesis are observedentirely through survey results. Data that is collected through SLR is usedto validate the obtained results. From the survey responses, it is observedthat among the five quality aspects that are identified through SLR, qualitymetrics is given more importance by large number of organisations and isfollowed by cost estimation. It is observed that elicitation is identified byless number of respondents. It is also observed that more number of respondentssuggested that there will not be any change in the focus of qualityrequirements depending on the quality aspects of RE process. It is identifiedthat there is a high impact of the selection of functional requirementson the quality requirements as per the survey results and majority of therespondents stated that the selection of quality requirements is dependenton the functional requirements. It is interesting that from the survey results,it is identified that almost half of the respondents’ organisations aretreating functional requirements equally and half of them are treating separately.Several challenges that may arise while implementing the qualityrequirements are also identified through both SLR and survey. Conclusions. This thesis help the further researches to get a detailed ideaon quality requirements, their usage in the organisations and the challengesfaced by them while implementing quality requirements. As this study involvedseveral observations that are related to the influence of functionalrequirements on quality requirements and the relation between the managementof quality requirements and RE process, it serves as a reference forfurther studies on quality requirements and gives scope to derive many newideas related to the maintenance of quality requirements. This work can befurther improved by considering large population of survey.