Analyzing Requirements in an Operational Viewpoint

Abstract

This is the first of three chapters spelling out the MBSAP methodology in detail. The Operational Viewpoint (OV) transforms a customer’s requirements, which may be documented in a Capabilities or Requirements Database, into an architectural context by mapping them into a high-level definition of system structure, behavior, information content, services, and other content. We address the creation of a system requirements baseline, including the important distinction between function and nonfunctional requirements. We describe the successive activities involved in creating the model while recognizing that the process is inherently both parallel and interactive in treating the various Perspectives of the OV. We present the two system examples that are used throughout the book, the E-X Airborne sensor Platform and a family of Smart Microgrids. We then define a set of architecture styles that may shed light on the fundamentals of architecture for a system category. We apply the diagrams and techniques from Chap. 2, especially Block, Use Case, and Activity Diagrams, and introduce the use of model element specifications to fully define the architecture. We discuss in detail the process of creating the Perspectives of the OV. We show briefly the equivalent content of an OV for the very different case of the Smart Microgrid. We conclude the chapter with a short discussion of executable architecture, which will be developed in more detail in later chapters. The chapter objective is the reader will be able to create an OV in a SysML model using the sequence of activities in the MBSAP methodology to create a requirements baseline and transform it into a high-level architecture.