This paper presents a systems life cycle and a structured design method which are tailored towards the construction of real-time systems in general, and hard real-time systems in particular. The standard systems life cycle is modified to take into account the expression and satisfaction of non-functional requirements. The HOOD design method is extended to support abstractions which explicitly cater for the characteristics and properties of hard real-time systems. The new method is called HRT-HOOD (Hard Realtime HOOD). 1. Introduction The most important stage in the development of any real-time system is the generation of a consistent design that satisfies an authoritative specification of requirements. Where real-time systems differ from the traditional data processing systems is that they are constrained by non-functional requirements (e.g. dependability and timing). Typically the standard design methodologies do not cater well for expressing these types of constraints. The objective...

Local area networks are increasingly used as a basis for distributing or integrating functionality in real-time industrial systems, for example in discrete parts manufacturing or in process control. These distributed systems are composed of many parts and having widely different forms and functions. To build and maintain correctness and efficiency in one of these systems would involve coordination of the different stages in the design life cycle of the system. This thesis presents a framework that will allow engineers and designers to study the different options of a design from early stages in its life cycle to its completion. Provided in this framework is a discrete event simulation architecture for evaluation of the different options, coupled to a knowledge-based system that provides tech...