Requirements Engineering that Balances Agility of Teams and System-level Information Needs at Scale

Context: Motivated by their success in software development, large-scale systems development companies are increasingly adopting agile methods and their practices. Such companies need to accommodate different development cycles of hardware and software and are usually subject to regulation and safety concerns. Also, for such companies, requirements engineering is an essential activity that involves upfront and detailed analysis which can be at odds with agile development methods. Objective: The overall aim of this thesis is to investigate the challenges and solution candidates of performing effective requirements engineering in an agile environment, based on empirical evidence. Illustrated with studies on safety and system-level information needs, we explore RE challenges and solutions in large-scale agile development, both in general and from the teams’ perspectives. Method: To meet our aim, we performed a secondary study and a series of empirical studies based on case studies. We collected qualitative data using interviews, focus groups and workshops to derive challenges and potential solutions from industry. Findings: Our findings show that there are numerous challenges of conducting requirements engineering in agile development especially where systems development is concerned. The challenges discovered sprout from an integration problem of working with agile methods while relying on established plan-driven processes for the overall system. We highlight the communication challenge of crossing the boundary of agile methods and system-level (or plan-driven) development, which also proves the coexistence of both methods. Conclusions: Our results highlight the painful areas of requirements engineering in agile development and propose solutions that can be explored further. This thesis contributes to future research, by establishing a holistic map of challenges and candidate solutions that can be further developed to make RE more efficient within agile environments

On the real world practice of Behaviour Driven Development

Surveys of industry practice over the last decade suggest that Behaviour Driven Development is a popular Agile practice. For example, 19% of respondents to the 14th State of Agile annual survey reported using BDD, placing it in the top 13 practices reported. As well as potential benefits, the adoption of BDD necessarily involves an additional cost of writing and maintaining Gherkin features and scenarios, and (if used for acceptance testing,) the associated step functions. Yet there is a lack of published literature exploring how BDD is used in practice and the challenges experienced by real world software development efforts. This gap is significant because without understanding current real world practice, it is hard to identify opportunities to address and mitigate challenges. In order to address this research gap concerning the challenges of using BDD, this thesis reports on a research project which explored: (a) the challenges of applying agile and undertaking requirements engineering in a real world context; (b) the challenges of applying BDD specifically and (c) the application of BDD in open-source projects to understand challenges in this different context. For this purpose, we progressively conducted two case studies, two series of interviews, four iterations of action research, and an empirical study. The first case study was conducted in an avionics company to discover the challenges of using an agile process in a large scale safety critical project environment. Since requirements management was found to be one of the biggest challenges during the case study, we decided to investigate BDD because of its reputation for requirements management. The second case study was conducted in the company with an aim to discover the challenges of using BDD in real life. The case study was complemented with an empirical study of the practice of BDD in open source projects, taking a study sample from the GitHub open source collaboration site. As a result of this Ph.D research, we were able to discover: (i) challenges of using an agile process in a large scale safety-critical organisation, (ii) current state of BDD in practice, (iii) technical limitations of Gherkin (i.e., the language for writing requirements in BDD), (iv) challenges of using BDD in a real project, (v) bad smells in the Gherkin specifications of open source projects on GitHub. We also presented a brief comparison between the theoretical description of BDD and BDD in practice. This research, therefore, presents the results of lessons learned from BDD in practice, and serves as a guide for software practitioners planning on using BDD in their projects

Requirements Engineering Challenges of Supporting Agile Teams in System Development

Context: Agile methods have attracted many companies due to their reported benefits of short time-to-market and improved quality outputs. In the systems development context, additional constraints apply e.g. as a result of scale or parallel development of hardware and software. Traditionally, stage-gate processes with a focus on up-front requirements analysis are common in large- scale systems engineering. These processes clash with the companies’ desire to become more agile.Objective: The aim of this thesis is to discover challenges that new requirements engineering approaches should address to enable agile system devel- opment at scale (RE4Agile). With a focus on value and building system understanding, we explore these challenges from the perspective of the agile development teams.Method: To meet our aim, we conducted a series of empirical studies based on case studies, and a secondary review to explore the problem domain while deriving challenges and potential solutions from industry and literature respectively.Findings: Our findings show that there are numerous challenges of conducting requirements engineering in agile development especially where systems development is concerned. These challenges relate to user value and overall system understanding. However, there are some cross-cutting concerns, e.g safety- critical development, that have generated much interest both from practitioners and academicians at large.Conclusions: The challenges discovered sprout from an integration problem of working with agile methods while using the already existing processes as well. However, solution candidates exist and our future research aims to validate some of the solution candidates in the view of deriving new RE approaches. This thesis contributes to such future research, by establishing a holistic map of challenges that allows to assess whether a given solution is beneficial in the larger context or whether it over-optimizes only one area