Web site evolution via transaction reengineering

In a transaction-oriented Web site, the user executes a series of activities in order to carry out a specific task (e.g., purchase an airplane ticket). The manner in which the activities can be executed is a consequence of the transaction design, partially influenced by the constraints implied by the business model underlying the Web application. Unfortunately, many Web sites are constructed with the transaction design hidden in the overall system implementation. The result is a system with unpredictable workflow, which can make evolution difficult. This paper presents a technique for Web site evolution via transaction reengineering. The reengineering process consists of the recovery of the "as-is" design model of a Web application transaction, an analysis of the result to determine desirable restructuring options, and a redesign of the transaction model based on this analysis. The reengineering process relies on formalism that is a user-centered extension of the transaction design model of the ubiquitous Web applications (UWA) framework. The goal of the reengineering process is to emerge with a transaction design that better reflects the user experience and also facilitates disciplined evolution of the Web-based application. An example from the travel industry is used to illustrate the process.