Operationalization of lean thinking through value stream mapping with simulation and FLOW

Abstract

Background: The continued success of Lean thinking beyond manufacturing has led to an increasing interest to utilize it in software engineering (SE). Value Stream Mapping (VSM) had a pivotal role in the operationalization of Lean thinking. However, this has not been recognized in SE adaptations of Lean. Furthermore, there are two main shortcomings in existing adaptations of VSM for an SE context. First, the assessments for the potential of the proposed improvements are based on idealistic assertions. Second, the current VSM notation and methodology are unable to capture the myriad of significant information flows, which in software development go beyond just the schedule information about the flow of a software artifact through a process. Objective: This thesis seeks to assess Software Process Simulation Modeling (SPSM) as a solution to the first shortcoming of VSM. In this regard, guidelines to perform simulation-based studies in industry are consolidated, and the usefulness of VSM supported with SPSM is evaluated. To overcome the second shortcoming of VSM, a suitable approach for capturing rich information flows in software development is identified and its usefulness to support VSM is evaluated. Overall, an attempt is made to supplement existing guidelines for conducting VSM to overcome its known shortcomings and support adoption of Lean thinking in SE. The usefulness and scalability of these proposals is evaluated in an industrial setting. Method: Three literature reviews, one systematic literature review, four industrial case studies, and a case study in an academic context were conducted as part of this research. Results: Little evidence to substantiate the claims of the usefulness of SPSM was found. Hence, prior to combining it with VSM, we consolidated the guidelines to conduct an SPSM based study and evaluated the use of SPSM in academic and industrial contexts. In education, it was found to be a useful complement to other teaching methods, and in the industry, it triggered useful discussions and was used to challenge practitioners’ perceptions about the impact of existing challenges and proposed improvements. The combination of VSM with FLOW (a method and notation to capture information flows, since existing VSM adaptions for SE are insufficient for this purpose) was successful in identifying challenges and improvements related to information needs in the process. Both proposals to support VSM with simulation and FLOW led to identification of waste and improvements (which would not have been possible with conventional VSM), generated more insightful discussions and resulted in more realistic improvements. Conclusion: This thesis characterizes the context and shows how SPSM was beneficial both in the industrial and academic context. FLOW was found to be a scalable, lightweight supplement to strengthen the information flow analysis in VSM. Through successful industrial application and uptake, this thesis provides evidence of the usefulness of the proposed improvements to the VSM activities