JultikaUniversity of Oulu repository

Abstract

Since the publication of the agile manifesto twenty years ago, its influence on software projects has been steadily growing and organisations and managers now have another methodology to choose from in addition to waterfall.

The question remains, however, whether software managers fully consider both methodologies and how easy it is for management to determine which methodology is the best fit for their project. This thesis will investigate the two main software development methodologies, waterfall and agile, and determine the critical success factors for each one using the research literature. Based on the critical success factors and an exploration of what makes each methodology powerful, selection criteria for choosing one or the other methodology will then be presented as a tool for helping management select the correct methodology.

The research questions of this thesis are:

RQ1: What are the core elements and key characteristics of agile and waterfall software development methodologies?

RQ2: What are the critical success factors for agile and waterfall software development methodologies?

RQ3: Which criteria to use when selecting agile or waterfall?

A meta-analysis of critical success factors is carried out across ten research papers, which are systematic literature reviews and in total comprise 298 articles and 550 surveys. Based on their output, the critical success factors are ranked in importance and are used to build some selection criteria to help management determine when a project would benefit more from using one software methodology over the other.

The thesis will provide a detailed definition and core characteristics of agile and waterfall which will be used as a foundation for linking the methodology theory to the critical success factors and selection criteria.

The overall aim of this thesis is to discover if agile is always the correct methodology for software development, and if not, to help managers determine when agile should be used. Management will be able to select the correct methodology based on the characteristics of their project and map those to the critical success factors in this thesis.

The important findings of the thesis are that it is rare for a project to be agile or waterfall and therefore selecting the correct methodology is not so black and white. The ideal methodology is one that is customised for the unique project. Factors that are especially important to consider are customer participation, team competency, top management support and specification changes.

The results of this thesis can be used by project managers to increase the success of their projects by changing or modifying their methodology or by changing certain key factors in their project, e.g., increasing customer participation during the development life-cycle.