I have seen many a new textbook come to the market advancing the use of a new and novel approach to specifying system and/or software requirements. All too often these approaches breakdown when you try to implement them because not all of the details have been worked out. As a direct consequence, users of the methodology experience considerable pain because they have to mature the methodology and address the details as they try to develop their requirements specifications.
In contrast, this book provides its readers with a tried and true approach to systems/software requirements specification and analysis. The book steps you through the Embedded Computer Systems Analysis and Modeling (ECSAM) method. It shows you how to use the methodology to develop static and dynamic models of the system using an end-to-end example. The book emphasizes how to capture the functional, interface and performance requirements by overlaying the static with dynamic models and by verifying the results via analysis as they are generated. In addition, the book takes operational considerations into account as the evolving specification is developed and tested for completeness and consistency. The book also shows you how to decompose the system requirements to the subsystem level and test for correctness. Results are easy to understand because the methodology uses familiar graphical representations that adhere to well-defined semantics and strict modeling rules (functional flow diagrams, state charts, etc.) to portray its outputs. Most importantly, the book provides the reader with insights into what to look for and what not. This is what I find missing in most of the newer and more revolutionary works on the topic.
The ECSAM methodology seems applicable to many classes of systems which are driven by performance and operational considerations. The book is extremely useful for those who want to use a methodology that permits them to develop a robust and consistent set of requirements for a system or subsystem.
