This dissertation proposes and evaluates a consolidated design methodology for web-based emergency management decision support systems (WEM-DSSs). The development of the proposed methodology draws upon a literature review which crosslinks substantive topics related to evolving theoretical paradigms in disaster research and the role of information systems within organizations, and competing approaches to the development of GIS and participatory decision support systems. As a conclusion of the literature review, it was suggested that a good software development methodology should be balanced between agility and discipline. Due to the nature of this research, a mixture of Extreme Programming and Capability Maturity Integration approaches with an emphasis on agility is proposed. Then the design of the proposed methodology is refined and tested through a case study that seeks to develop a WEM-DSS for the emergency managers working in Oklahoma. The methodology's effectiveness is mainly evaluated by investigator's ability to follow proposed methodological tasks, ability to involve sufficient user input and ability to follow proposed timeline.

The findings of this research enhance our understanding of delivering geographic information to users, and drawing user input from emergency management communities. From a systems development point of view, this study shows that XP and CMMI are in fact compatible with each other. From an empirical viewpoint, the study shows a complete process of following a methodology that is implemented for developing a WEMDSS. Finally, this research delivers a technical product that is built upon user input. This product employs ArcGIS Silverlight API, Microsoft Silverlight and service oriented architectures.