South Africa has one of the highest measures of economic inequality and one of the worst performing basic education systems in the world. The majority of learners from poorer communities are attending dysfunctional schools, while a minority of learners from richer communities are achieving adequately in a functional system. The economic disparity creates an intuition that allocating more funds can solve low academic performance, but this approach has yielded little return for a number of years. In this dissertation, the impact of school leadership on learners' academic performance is considered in the South African context. School management is a systemic concept and elements thereof cannot be analysed in isolation. A series of system dynamics simulation models is developed to understand the effect of various school management interventions on communities, teachers, resources, and learners within the basic education system. The School Effectiveness Model simulates the South African basic education system and reveals that improvement interventions must be made early, continously and in multiple areas for them to be effective. The Teacher Effectiveness Model simulates the career progression of Western Cape public teachers and reveals that the number of the teachers appointed in a primary school has a greater impact on their effectiveness than the quality of the teachers appointed. The Early Childhood Development Model simulates the preschool career of Western Cape children and reveals that improving the quality of Early Childhood Development programmes has a greater impact on their primary school readiness than increasing the number of children enrolled into programmes. The Primary School Model simulates the progression of learners from Grade 1 to Grade 7 in the Western Cape and reveals that improving learners' social circumstance at home has a greater impact on their academic performance than improving their classroom experience. Finally, the expanded School Effectiveness Model brings all the models together to reveal that a combination of interventions is needed to decrease the academic performance gap between poorer and richer communities within the Western Cape.