The Impact of Requirements on Systems Development Speed: A Multiple-Case Study in Automotive

Automotive\ua0manufacturers have historically adopted rigid\ua0requirements\ua0engineering processes. This allowed them to meet safety-critical\ua0requirements\ua0when producing\ua0a\ua0highly complex and differentiated product out of the integration of thousands of physical and software components. Nowadays, few software-related domains are as rapidly changing as the\ua0automotive\ua0industry.\ua0In\ua0particular, the needs of improving\ua0development\ua0speed\ua0are increasingly pushing companies\ua0in\ua0this domain toward new ways of developing software.\ua0In\ua0this paper, we investigate how the goal to increase\ua0development\ua0speed\ua0impacts how\ua0requirements\ua0are managed\ua0in\ua0the\ua0automotive\ua0domain. We start from\ua0a\ua0manager perspective, which we then complement with\ua0a\ua0more general perspective. We used\ua0a\ua0qualitative\ua0multiple-case\ua0study, organized\ua0in\ua0two steps.\ua0In\ua0the first step, we had 20 semi-structured interviews, at two\ua0automotive\ua0manufacturers. Our sampling strategy focuses on manager roles, complemented with technical specialists.\ua0In\ua0the second step, we validated our results with 12 more interviews, covering nine additional respondents and three recurring from the first step.\ua0In\ua0addition to validating our qualitative model, the second step of interviews broadens our perspective with technical experts and change managers. Our respondents indicate and rank six aspects of the current\ua0requirements\ua0engineering approach that\ua0impact\ua0development\ua0speed. These aspects include the negative\ua0impact\ua0of\ua0a\ua0requirements\ua0style dominated by safety concerns as well as decomposition of\ua0requirements\ua0over many levels of abstraction. Furthermore, the use of\ua0requirements\ua0as part of legal contracts with suppliers is seen as hindering fast collaboration. Six additional suggestions for potential improvements include domain-specific tooling, model-based\ua0requirements, test automation, and\ua0a\ua0combination of lightweight upfront\ua0requirements\ua0engineering preceding\ua0development\ua0with precise specifications post-development. Out of these 12 aspects, seven can likely be addressed as part of an ongoing agile transformation. We offer an empirical account of expectations and needs for new\ua0requirements\ua0engineering approaches\ua0in\ua0the\ua0automotive\ua0domain, necessary to coordinate hundreds of collaborating organizations developing software-intensive and potentially safety-critical\ua0systems