Software complexity: An aid to software maintainability

Abstract Recent estimates that 40–70% of software cost is being spent after the software has been tested and delivered by the development contractor, makes the area of post-delivery maintenance of software a prime candidate for major technological effort with potentially high return on investment. Maintenance is most affected by software complexity, and if complexities could somehow be identified, then maintenance procedures could be adjusted accordingly. What is needed is some method of pin-pointing the characteristics of a computer program that are difficult to maintain and measuring the degree of their presence (or lack of it). This paper discusses a number of software complexity metrics reported in the last few years and examines the applicability of these complexity metrics to form a software maintainability point of view.