Model-Based Systems Engineering and Requirements Definition

Learn how to integrate model-based systems engineering (MBSE) with mission-driven requirements to create a connected framework that delivers reliable solutions designed with key objectives. This book uses real-world examples to demonstrate how clear requirements and smart modeling lead to systems that work better, cost less to fix, and meet their goals the first time.
Author, Air Force veteran, and Chief Systems Engineer Dennis Hansen draws on 60 years of experience managing full system lifecycles across military, government, and private sectors. This foundation drives a practical approach to understanding how design and operations drive engineering success. First, learn the end-user definition of the system function (i.e., the mission), before identifying capabilities needed to perform this function. The book then explains the transition from capabilities to activities and functional model views, and the associated requirement definitions. From there, you will learn how modeling can shift from architecture to SysML design views, continuing with both model and requirement definitions. Finally, you’ll discover how models can be used to aid generation and refinement of test plans and procedures as the system evolves, and how these models support ongoing system sustainment and improvement.
Throughout, you’ll encounter practical examples and diagrams to illustrate how to connect key concepts. This book fills a gap left by other books that treat requirements and models separately, showing how tying them to mission goals leads to better results. Practical guidance covers incorporating security early, using proven standards like NIST 800-53, and applying frameworks such as DoDAF or SysML. Additionally, each chapter includes a guide and Agile planning tips to help you apply these concepts step by step.
What You Will Learn:
- Define the mission to establish a clear system purpose.
- Identify the capabilities needed to achieve the mission.
- Develop architecture and requirements that deliver these capabilities through detailed activities
- Apply Agile scheduling to organize development activities.
Who This Book is for:
Intermediate-level system engineers, software engineers and management, particularly in, but not limited to, government agencies.

Dennis Hansen's career began with Air Force assignments as an airborne navigation aids technician. After earning his commission, he served in several key roles: Chief of the Plans and Programs Branch at SAC/1st Communications Group, Chief of the Systems Engineering & Training Branch at the 4000 Aerospace Applications Group, and Manager of Strategic Ground Systems for the Defense Meteorological Satellite Program. His experience provided a deep understanding of how design errors impact system operations — first as a technician during the Air Force’s test phase of the B-58 bomber, and later, after completing his BSEE, in managing the planning and transition of systems into operational service.
Following his Air Force retirement, Mr. Hansen worked at Harris Corporation (now L3Harris Technologies) for 40 years as a Systems Engineer and Chief Systems Engineer on multiple programs. Notably, he contributed as Chief Systems Engineer to the development of a new ground system for the GOES-R weather satellite program, covering all aspects from antennas, command and telemetry, and networking to systems management and processing of received payload data.
Throughout his career, Mr. Hansen has gained broad experience across the full system lifecycle — from addressing the potential impacts of faulty design during operation, to managing system acquisitions, and ultimately leading the development of systems acquired by government agencies.