When to automate software testing? decision support based on system dynamics: an industrial case study

Software test processes are complex and costly. To reduce testing effort without compromising effectiveness and product quality, automation of test activities has been adopted as a popular approach in software industry. However, since test automation usually requires substantial upfront investments, automation is not always more cost-effective than manual testing. To support decision-makers in finding the optimal degree of test automation in a given project, we propose in this paper a simulation model using the System Dynamics (SD) modeling technique. With the help of the simulation model, we can evaluate the performance of test processes with varying degrees of automation of test activities and help testers choose the most optimal cases. As the case study, we describe how we used our simulation model in the context of an Action Research (AR) study conducted in collaboration with a software company in Calgary, Canada. The goal of the study was to investigate how the simulation model can help decision-makers decide whether and to what degree the company should automate their test processes. As a first step, we compared the performances of the current fully manual testing with several cases of partly automated testing as anticipated for implementation in the partner company. The development of the simulation model as well as the analysis of simulation results helped the partner company to get a deeper understanding of the strengths and weaknesses of their current test process and supported decision-makers in the cost effective planning of improvements of selected test activities.