Concurrent plan-driven versus sequential agile development: keeping up appearances in embedded systems development

The functionality of many of today's new, ‘intelligent’ products, such as smartphones, originates from the use of embedded systems that include both hardware and software. Hardware development is usually managed using a plan-driven archetype, whereas in software development agile methods have become the dominant archetype. Various studies have suggested that companies can use both agile and plan-driven methods simultaneously in one project, for example by dividing projects in independent modules. However, it is unclear how to consolidate these two archetypes when modularity is not an option - as in embedded systems. To address this, we conduct an in-depth case study of an embedded systems development project in the automotive industry. We use a process research approach to explore the project over time. Subsequently, we draw on systems thinking to illustrate the self-reinforcing nature of project problems over time, ultimately leading the project to fail. Our findings illustrate how the software team is forced to comply with the plan-driven demands of the manufacturer’s hardware team. To solve this apparent role conflict, the software team resorts to ‘keeping up appearances’: it forgoes its agile development cycles and focuses on feature development only without frequent testing. This behavior results in an increasing (and regenerative) number of undetected software issues. When the team finally detects the huge amount of rework, there is no time remaining and the project is terminated by the manufacturer. Based on our analysis we provide suggestions to allow both hardware and software teams to work with their own preferred method.