Estimating Time to Develop Software

Abstract

The most devastating task ever given to the computer system manager, is that of estimating the manpower and time to develop software. Software development has become almost completely out of control in terms of estimating the manpower and time needed for the complete job, from interpretation of the requirements to the operational readiness date. Just as the hardware design engineer never reaches the ultimate design and thus never concludes his job, so goes the software designer. The difference is, hardware design managers have grown up in this environment and therefore know the pitfalls and stopping points of producing a good, reliable product. The software design manager is less qualified because the field is relatively new, it is very complex, and computer hardware technology is expanding so rapid that software designers cannot catch up. This paper is designed to provide the software development manager categories and rules of thumb for estimating time and manpower requirements for each category of software development. In addition to establishing the standard milestones such as requirements definition, specification, design, coding, checkout, verification and validation, consideration is given on how to keep the Ford requirement from turning into a Cadillac capability.