Agile versus Waterfall Project Management: Decision Model for Selecting the Appropriate Approach to a Project

Procedural models for project management can be differentiated into plan-driven methods which follow a classical waterfall process and agile methods which follow an iterative, test-driven approach. This paper answers the following research questions: What are the differences, benefits, and constraints of these two approaches from a practitioner’s point of view? How can a decision model be set up to select the most appropriate approach for a concrete project? This study develops a decision model for the selection of a procedural model for project management which is based on the modelling process described by Adam (1996). The research gap was identified based on a systematic and comprehensive analysis of the literature following Vom Brocke et al. (2009), which reflects the state-of-research. Insights gained were compared with empirical data from 15 expert interviews across different industries in Germany. The presented model systematically supports the selection of an appropriate procedural model for a concrete project based on 15 criteria subsumed under the following categories: scope, time, costs, organization context, and project-team characteristics. It closes a relevant research gap, both from a scientific perspective and from the practitioners’ view. Expert interviews ensure practical relevance and significantly expand the state-of-research with regards to decision support on the project-management approach.