To cope effectively with high levels of requirementvolatility and frequent system changes, practitionershave increasingly adopted iterative and agilemethodologies in Web development and maintenance.Despite the increasing acceptance of the agilemethods, empirical evidence on its effectiveness ismainly anecdotal. There is a need to understand thedynamic process of agile methodologies through amore structured analytical process. In this paper,we attempt to model the influences of the values ofthe agile methodologies by analyzing factors thatimpact on productivity during agile web developmentand maintenance phases. Influence diagramsare used to model an agile method, namely the"Critical Feature Method". Qualitative analysis ofinfluence factors in the ma] or maintenance processis conducted. Major influences to the major projectconcern "velocity of the exploration phase" aremodeled. This model is an important step towardsthe quantitative modeling of agile methodologies.Our next research step will be the simulation of theCritical Feature Method based on the qualitativemodel developed in this paper. The results from theCritical Feature Method could be adapted to otheragile methodologies in the future research.
