Shutdown projects are known as strategic components used for maximizing production throughput and increasing the reliability of the plant. Research has shown that project managers are faced with a number of challenges when implementing shutdown projects. This research examined how shutdown project success is perceived based on the views of those engaged in these projects in South Africa, studied the factors that can contribute towards improving the project outcome, and developed a conceptual model for examining the significance of these factors on project success. An extensive evaluation of existing literature was conducted, from which this study extracted a set of success criteria used to assess the outcome of shutdown projects and success variables in shutdown projects. A conceptual model was developed, which examines the association between the critical success factors and project success. The research design of this study was guided by the positivist research philosophy. A cross-sectional survey was undertaken to collect data from participants involved in shutdown projects in South Africa. The sample was selected using purposive sampling. The investigation resulted in a sample of 246 valid responses being received. The hypothesised association between project success and the critical success factors was analysed using structural equation modelling. In this research study, success is regarded as a multi-dimensional construct characterised by project efficiency and organisational success. The study established that success in shutdown projects is accomplished when the project is concluded according to the project costs, time, commissioning incidences,health safety and environmental (SHE) specifications; according to the needs of stakeholders and the profitability of the business. Further, the following categories of success factors critical for shutdown project success were established: project management actions, competence of the project manager, organisational success, competence of the project team and project characteristics. Of these critical success factors, the overall success of shutdown projects was significantly affected by organisational factors. Although project characteristics were found to be significant for the project efficiency dimension of project success, project management actions and competence of the project team were found to be significant for the organisational success dimension of project success. The findings of this research therefore provide a holistic view of the measures used to evaluate the outcome of shutdown projects and guide project managers to the critical success factors that can be considered when improving the success of their shutdown projects. / School of Computing / D. Phil.