What this book covers
Chapter 1, Introduction to Systems Engineering, provides a brief history of systems engineering, then provides an overview of exactly what we mean by systems engineering and what differentiates it from other disciplines of engineering. The real-world, pragmatic need for systems engineering is explored by considering the increased complexity of today's systems, the need for effective and efficient communication, and the need for a clear, context-based understanding of different stakeholders' views of our systems. The practical issues with implementing systems engineering successfully in an organization are also discussed.
Chapter 2, Model-Based Systems Engineering, introduces the most effective and efficient way to realize systems engineering in the form of Model-Based Systems Engineering (MBSE). MBSE allows systems engineers to understand systems by developing a model to represent the single source of truth and how to use this as the basis for all systems engineering activities.
The system and its model are discussed, along with the importance of a framework that provides the blueprint for the model and various visualization techniques, such as SysML. This is then expanded to include tools and best practices to ensure that the model is as effective as possible.
Chapter 3, Systems and Interfaces, describes exactly what we mean by a system and the different types of systems that exist, including systems of systems. The structure of systems and their system elements – subsystems, assemblies, and components – are discussed as well as how they are arranged in hierarchies. The importance of understanding the relationships between these system elements is explained and how this impacts the system behavior. Behavioral concepts such as states, modes, and interactions are then defined. The key concept of the interfaces that connect a system together and to other systems is explained and the requirements for such interfaces are defined.
Chapter 4, Life Cycles, introduces the concept of life cycles and how they control the evolution of a system. Different types of life cycles are introduced and the importance of understanding the potentially complex relationships between them is stressed. The basic construct of a life cycle, the stage, is introduced and an example system life cycle based on best practice is defined. The behavior of life cycles is then described by considering life cycle models and some of the different types of execution of models. The international best practice model of ISO 15288 and its processes are used as a reference for these life cycle stages.
Chapter 5, Systems Engineering Processes, introduces the concepts of processes and their related elements, such as activities, artifacts, stakeholders, and resources. The importance of effective processes that define the overall approach to systems engineering is emphasized. The four different categorizations of processes are introduced and then a description of each of these four categories and their associated processes is provided. The international best practice model of ISO 15288 and its processes are used as a reference for these processes.
Chapter 6, Needs and Requirements, explains the importance of needs along with different types, specifically requirements. The whole area of stakeholder needs identification and analysis is described, along with the views necessary to understand the different aspects of needs. Describing needs using text is introduced, and then how to define contexts that may be used for the basis of use cases, as well as how these use cases may be validated by describing scenarios. There is then a discussion of how needs fit into the systems life cycle, which processes are relevant, and how to comply with them.
Chapter 7, Modeling the Design, discusses how solutions may be defined by developing effective designs. Various levels of abstraction of design are discussed, such as architectural design and detailed design. Also, different aspects of design, such as logical, functional, and physical designs, are introduced and the relationships between them are defined. There is then a discussion of how design fits into the systems life cycle, which processes are relevant, and how to comply with them.
Chapter 8, Verification and Validation, introduces how the system may be demonstrated to be fit for purpose by introducing the concepts of verification (the system works) and validation (the system does what it is supposed to do). A number of techniques are introduced and described that show how verification and validation may be applied at different levels of abstraction of the system and an overview of other techniques that may be used is provided. There is then a discussion of how verification and validation fit into the systems life cycle, which processes are relevant, and how to comply with them.
Chapter 9, Methodologies, describes some of the most widely used methodologies for systems engineering that are used in modern industry. Some of these use specific techniques while others are variations on the standard life cycle model. Each is described at a high level, examples are given, and a summary of the methodology's effective use is provided. There is then a discussion of how methodologies fit into the systems life cycle, which processes are relevant, and how to comply with them.
Chapter 10, Systems Engineering Management, provides an overview of some of the key management processes and associated techniques that need to be considered and how they can be implemented. The relationship between management techniques and technical techniques is also discussed. There is then a discussion of how design fits into the systems life cycle, which processes are relevant, and how to comply with them.
Chapter 11, Best Practices, is a short chapter that provides a set of information that can be used to continue systems engineering in your own organizations. This includes modern standards and other best practice sources, such as guidelines and also a list of organizations who actively promote systems engineering and provide valuable resources.