\"Multivocal Literature Review of Models for Testing Process Assessment and Improvement\"

Testing process models provide structured testing practices that help teams/organizations to identify gaps in existing testing processes, implement best practices and achieve high quality testing. Additionally, these models provide career guidance for software test practitioners. Many of these models were introduced decades ago. Since then, they have been evolved with latest research and user practices. It is not always easy to get a consolidated list of testing models suitable for practical use. The last detailed analysis of testing models was presented in 2019. Therefore, it is unclear what models currently exist for testing process assessment and improvement. This Multivocal Literature Review (MLR) explores existing models, analyze their comparisons and find out which of these models are suitable for practical use. This MLR was performed on 907 studies from which 20 distinct models were identified for testing process assessment and improvement.