For any set of application requirements there are potentially many system designs which can satisfy the required properties. A particular solution is usually arrived at by following a design method, either formally or informally. For hard real-time systems the situation is no different. The problem, however, is that current design methods do not adequately address the temporal characteristics of these systems. A hard real-time design method should guide the designer to a solution which can be analysed to ensure that the timing requirements have been met. The goal of this book is to present a structured design method which facilitates the construction and analysis of hard real-time systems. The book consists of three parts and five appendices.
Part 1 summarises our overall approach to the engineering of hard real-time systems, and indicates how the software development life cycle can be modified so that it addresses both functional and non-functional application requirements. Using the object-based framework, we identify the abstractions which must be available to the designer to guide the software development process towards the construction of predictable and analysable systems.
The overall goal of the project was to show how hard real-time systems can be designed and implemented in Ada. In Part 2 we show how HRT-HOOD designs can be systematically translated into Ada 95 and Ada 83.
In this part of the book two case studies are presented. The first involves the control of a pump in a mine drainage system; it is a pedagogical study designed to illustrate many of the features available in HRT-HOOD.
The second is the redesign of a real system so that the method can be evaluated. The system is the attitude and orbital control system for the Olympus Satellite.
There are five appendices: