11 - System Design

Abstract

This chapter discusses system design. The goal of system design is to allocate the requirements of a large system to hardware and software components. The system design activity starts after the system requirements analysis has been completed. The starting point is a system requirements specification and the documentation created during the system requirements analysis. The transitioning from the system requirements analysis to system design is usually a nontrivial exercise as there is seldom a single, obvious solution that presents itself to the designers. Sometimes, the transition is made easier by customer documentation that includes a partitioning. The first step in the system design phase is the partitioning activity where a large system is decomposed into smaller entities to reduce the overall complexity, and to allow subsequent development of architectural modules by several teams of developers. The primary purpose of partitioning is to decompose the requirements of a large real-time system into smaller, manageable units that can be designed as architectural entities by teams of hardware and software engineers. The system design phase consists of the decomposition of a large system into partitions that can execute as independent entities in a distributed configuration. The configuring step is performed in close concert with the partitioning.