Rugby - A Process Model for Continuous Software Engineering

Software is developed in increasingly dynamic environments. Organizations need the capability to deal with uncertainty and to react to unexpected changes in requirements and technologies. Agile methods already improve the flexibility towards changes and with the emergence of continuous delivery, regular feedback loops have become possible. The abilities to maintain high code quality through reviews, to regularly release software, and to collect and prioritize user feedback, are necessary for continuous software engineering. However, there exists no uniform process model that handles the increasing number of reviews, releases and feedback reports. In this dissertation, we describe Rugby, a process model for continuous software engineering that is based on a meta model, which treats development activities as parallel workflows and which allows tailoring, customization and extension. Rugby includes a change model and treats changes as events that activate workflows. It integrates review management, release management, and feedback management as workflows. As a consequence, Rugby handles the increasing number of reviews, releases and feedback and at the same time decreases their size and effort. Rugby reduces the time between development and usage of software features in development projects. When used in education, Rugby reduces the time between teaching and exercising concepts to improve knowledge retention. We applied Rugby in three case studies: (1) in 62 university capstone projects with about 500 students, (2) in a lecture with 57 team projects and about 400 students, and (3) in 8 industry projects with 31 professionals in a company. Empirical evaluations demonstrate that Rugby significantly increases the frequency and quality of interactions between developers and users as well as instructors and students. (1) The introduction of Rugby increased the number of students in capstone projects who have improved their skills in configuration and release management from 40 % to 80 %. Rugby led to 96 code reviews, 64 releases and 27 feedback reports on average per team in 2014. (2) 77 % of the lecture students who participated in the exercises are confident to apply continuous software engineering workflows in future projects. (3) The 8 industry projects tailored Rugby to their needs and were able to reduce the time effort for integration and delivery from hours to minutes, while increasing the frequency of releases.