N 89 - 16329 - the Benefits Bottom - up Design

This paper examines an inconsistency in generic ’top-down’ design methods and standards employed in the implementation of reliable software. Many design approaches adopt top-down ordering when defining the structure, interfaces, and processing of a system. However, strict adherence to a top-down sequencing does not permit accurate description of a system’s error handling functions. The design of a system’s response to errors is becoming critical as the reliability requirements of systems increase. This paper describes how top-down methods such as Object Oriented Design and Structured Design do not adequately address the issues of error handling, and suggests using a bottom-up substep within these methods to eliminate the problem.