On Groupthink in Safety Analysis: An Industrial Case Study

Context: In safety-critical systems, an effective safety analysis produces high-quality safety requirements and ensures a safe product from an early stage. Motivation: In safety-critical industries, safety analysis happens mostly in groups. The occurrence of "groupthink", under which the group members become concurrence-seeking, potentially leads to a poor safety assurance of products and fatalities. Objective: The purpose of this study is to investigate how groupthink influences safety analysis as well as how to reduce it. Method: We conducted a multi-case study in seven companies by surveying 39 members and interviewing 17 members including software developers, software testers, quality engineers, functional safety managers, hazard/risk managers, sales, purchasing, production managers and senior managers. Results: The TOP 10 phenomena of groupthink in safety analysis are: (1) The managers are too optimistic on the plan of safety analysis from norms. (2) The technical members overestimate their capability on avoiding risks. (3) The non-functional department is under negative stereotypes in safety analysis. (4) Non-technical members keep silence during safety analysis. (5) Team members keep consistent opinions with senior safety experts. (6) The team rationalizes the safety analysis solutions. (7) The safety analysts spontaneously freeze the safety-related documents. (8) The safety analyst has an illusion of invulnerability during verification. (9) The internal safety assessor rationalizes the safety assurance to a third party. (10) The team rationalizes the safety analysis for providing safety evidences. Furthermore, we found reasons like "cohesion" and "group insulation" and solutions like "inviting external expert" and "making key members impartial". Conclusion: There is groupthink in safety analysis in practice. Practitioners should look for the phenomena and consider solutions. However, the cases are limited to the investigated domains and countries.