Scheduled aircraft maintenance consists of a set of work tasks to be executed. This thesis focuses on improving the order in which these work tasks are executed. Because finding an optimum for these kind of problems is computationally intensive, the chosen approach is of heuristic nature, which is a practical method resulting in close-to-optimal solutions. In short, the model builds a schedule based on a set of rules and constraints, in which the work tasks with the highest priority are planned as early as possible in the maintenance check. Here, priority is the heuristic and based on minimizing the total length of the maintenance check. Because of the rule-based approach, the output of the model will only slightly change with similar sets of work tasks, leading to standardization of the maintenance. Lastly, as the model is semi-automatized, the model can both proactively as well as reactively generate schedules.