  The development of large, software-intensive systems is a complex undertaking
that we generally tackle by a divide and conquer strategy. Companies thereby
face the challenge of coordinating individual aspects of software development,
in particular between requirements engineering (RE) and software testing (ST).
A lack of REST alignment can not only lead to wasted effort but also to
defective software. However, before a company can improve the mechanisms of
coordination they need to be understood first. With REST-bench we aim at
providing an assessment tool that illustrates the coordination in software
development projects and identify concrete improvement opportunities. We have
developed REST-bench on the sound fundamentals of a taxonomy on REST alignment
methods and validated the method in five case studies. Following the principles
of technical action research, we collaborated with five companies, applying
REST-bench and iteratively improving the method based on the lessons we
learned. We applied REST-bench both in Agile and plan-driven environments, in
projects lasting from weeks to years, and staffed as large as 1000 employees.
The improvement opportunities we identified and the feedback we received
indicate that the assessment was effective and efficient. Furthermore,
participants confirmed that their understanding on the coordination between RE
and ST improved.
