Throughout twelve chapters, this third edition promises a restructure to include vital updates such as the inclusion of open-source software applications. With excel remaining the primary modeling and analysis application, the author introduces the following applications; SIPmath Modeler Tools, Cambridge Advanced Modeller (CAM), Gephi 0.9.2, SystemiTool2.0, R, and Vensim PLE 8.2.1. This textbook provides new and updated illustrative and diverse examples of systems such as hardware, organizations, policy, logistic supply chains, cyber protection software, and architecture to improve the students learning experiences and understanding. Decision Making in Systems Engineering and Management supports remote learning by including the ability for instructors to check on their students learning progress, enabling the ability to understand what topics they are finding most difficult. The additional appendices at the end of the book support students learning progress alongside the inclusion of new material to aid in updates made since the publication of the prior edition. Aforementioned new material includes; sections introducing risk-based cost estimating, approaches to performing system reliability estimating focused on reliability block diagrams, non-functional requirements and their challenges, and systemigram modeling and analysis.