Cost-Benefit Analysis of Usability Engineering Techniques

A methodology for computing the value of iterative usability work is presented using data from a series of three usability tests of each of two software applications. The cost-benefit analysis methodology provides software development managers a basis for making pragmatic decisions about human factors work. The projected dollar value of the reduction in end user time on an application task based on data from the first to the third test is compared to the costs of the usability work. The analysis shows a 2:1 dollar savings-to-cost ratio for a relatively small development project and a 100:1 savings-to-cost ratio for a large development project. Sources of additional savings are examined. Methodological techniques employed during the iterative usability testing are highlighted and the tradeoffs concerning use of these techniques for human factors, software development schedule, and economic reasons are discussed. Cost-benefit analysis is one of several mechanisms that generate product management support for human factors work and may facilitate a better understanding of the value of incorporating human factors work in software development.