Final answer:
Corrective actions are designed to remedy variances in project execution and are the measures that should lead to improvements in project performance. Although defect repairs and preventive actions are important, they serve different purposes and do not directly enhance project performance like corrective actions.
Step-by-step explanation:
Corrective actions should result in improvements in project performance. Corrective actions are measures taken to rectify any variances or deficiencies identified during project execution. They are focused on adjusting the project work to conform with the project management plan. For instance, if a project timeline is at risk due to delayed tasks, corrective actions such as reallocating resources or adjusting schedules might be implemented to bring the project back on track. Preventive actions are also important; they are proactive measures that aim to prevent potential problems from occurring in the first place. However, they do not directly result in performance improvements, instead, they ensure that performance does not degrade. Defect repairs involve fixing specific deliverables that are not meeting the agreed standards, which can improve the outcomes of a project but do not necessarily improve overall project performance. Lastly, product acceptance plans are documents that outline the process for verifying, inspecting, and accepting deliverables, which is not directly associated with improving project performance.