Software quality is perhaps one of the most sought-after attributes in product development, however; this goal is unattained. Problem factors in software development and how these have affected the maintainability of the delivered software systems requires a thorough investigation. It was, therefore, very important to understand software development problem factors that could help in not only reducing these incidences of software project failures yet also ensure friendly software maintainability. This study explored how systems development methodologies (SDMs) and the inclusion of quality assurance in all phases of the system development life cycle (SDLC) could help improve the software development process. Agile methodologies, the latest batch of SDMs that are most suitable in dealing with volatile business requirements, are likely to face the same challenges, as they required developers to drastically change their work habits and acquire new skills. The study provided a critical review of the extant literature on the acceptance of traditional SDMs and agile methodologies, and developed a conceptual framework for agile methodologies acceptance based on a knowledge management perspective. This framework provided guidance for future research into acceptance of agile methodologies and the inclusion of quality assurance in all phases of the SDLC. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]