Bottom-up Adoption of Continuous Delivery in a Stage-Gate Managed Software Organization

Context: Continuous delivery (CD) is a development practice for decreasing the time-to-market by keeping software releasable all the time. Adopting CD within a stage-gate managed development process might be useful, although scientific evidence of such adoption is not available. In a stage-gate process, new releases pass through stages and gates protect low-quality output from progressing. Large organizations with stage-gate processes are often hierarchical and the adoption can be either top-down, driven by the management, or bottom-up, driven by the development unit. Goal: We investigate the perceived problems of bottom-up CD adoption in a large global software development unit at Nokia Networks. Our goal is to understand how the stage-gate development process used by the unit affects the adoption. Method: The overall research approach is a qualitative single case study on one of the several geographical sites of the development unit. We organized two 2-hour workshops with altogether 15 participants to discover how the stage-gate process affected the adoption. Results: The stage-gate development process caused tight schedules for development and process overhead because of the gate requirements. Moreover, the process required using multiple version control branches for different stages in the process, which increased development complexity and caused additional branch overhead. Together, tight schedule, process overhead and branch overhead caused the lack of time to adopt CD. In addition, the use of multiple branches limited the available hardware resources and caused delayed integration. Conclusions: Adopting CD in a development organization that needs to conform to a stage-gate development process is challenging. Practitioners should either gain support from the management to relax the required process or reduce their expectations on what can be achieved while conforming to the process. To simplify the development process, the use of multiple version control branches could be replaced with feature toggles.