This research aimed to understand how the significant factors that lead to performance challenges across Nigeria's state-owned refineries operationalise to drive their sub-optimal performance. As such, unlike previous studies, this thesis proposed to develop a decision-support model to inform policy intervention measures that will address the refining problems from a holistic viewpoint. Using a literature search, the study identified several challenging factors, which it initially categorised within a political, economic, social, technical, environmental, and legal...