Maintaining behaviour driven development specifications: Challenges and opportunities

Abstract

In Behaviour-Driven Development (BDD) the behaviour of a software system is specified as a set of example interactions with the system using a "Given-When-Then" structure. These examples are expressed in high level domain-specific terms, and are executable. They thus act both as a specification of requirements and as tests that can verify whether the current system implementation provides the desired behaviour or not. This approach has many advantages but also presents some problems. When the number of examples grows, BDD specifications can become costly to maintain and extend. Some teams find that parts of the system are effectively frozen due to the challenges of finding and modifying the examples associated with them. We surveyed 75 BDD practitioners from 26 countries to understand the extent of BDD use, its benefits and challenges, and specifically the challenges of maintaining BDD specifications in practice. We found that BDD is in active use amongst respondents, and that the use of domain specific terms, improving communication among stakeholders, the executable nature of BDD specifications, and facilitating comprehension of code intentions are the main benefits of BDD. The results also showed that BDD specifications suffer the same maintenance challenges found in automated test suites more generally. We map the survey results to the literature, and propose 10 research opportunities in this area.