The need for purpose motivating project professionals to work on projects

Project work plays an increasingly important role in contemporary organisations, but its temporary and uncertain nature poses motivational challenges for project professionals. This dissertation examines what motivates project professionals to work on projects, focusing on the need for purpose. Purpose is defined as a psychological need that connects individual project work to organisational and societal impacts, manifesting through the achievement of project outcomes, creation of business value, and contribution to societal betterment. Positioned alongside autonomy, competence and relatedness within the self-determination theory (SDT) framework, purpose is explored through a three-phase mixed-methods design: a multiple case study of young professionals focused on different industries in the private sector, a large-scale survey assessing purpose across generations, and a single case study in the public sector. Findings from these diverse contexts show that purpose is a distinct and independent motivational driver. It enhances both short-term job satisfaction and long-term career sustainability and is particularly relevant for younger professionals and those working in highly regulated environments. The dissertation makes four main contributions. First, it extends SDT by establishing purpose as a fourth basic psychological need. Second, it bridges motivation theory and sustainable career research by demonstrating how purpose acts as a psychological anchor across transitions. Third, it provides contextual insights into how purpose manifests differently across industries and generations. Fourth, it offers practical implications for embedding purpose in leadership, talent development and project design. In doing so, it challenges prevailing assumptions within SDT and proposes a more purpose-oriented approach to understanding and supporting motivation in project-based work.