Effort models and effort estimates help project managers allocate resources, control costs and schedule, and improve current practices, leading to projects that are finished on time and within budget. In the context of Web development and maintenance, these issues are also crucial, and very challenging, given that Web projects have short schedules and a highly fluidic scope. Therefore, the objective of this chapter is to introduce the concepts related to Web effort estimation and effort estimation techniques. In addition, this chapter also details and compares, by means of a case study, three effort estimation techniques, chosen for this chapter because they have been to date the ones mostly used for Web effort estimation: Multivariate regression, Case-based reasoning, and Classification and Regression Trees. The case study uses data on industrial Web projects from Spanish Web companies.
The Web is used as a delivery platform for numerous types of Web applications, ranging from complex e-commerce solutions with back-end databases to online personal static Web pages (Mendes, Mosley, & Counsell, 2005a). With the sheer diversity of Web application types and technologies employed, there are a growing number of Web companies bidding for as many Web projects as they can accommodate. As usual, in order to win the bid, companies estimate unrealistic schedules, leading to applications that are rarely developed within time and budget (Mendes & Mosley, 2005).