Maintenance can represent a significant portion of the cost in asset intensive organisations (such as Sidel - a food processor), as breakdowns have an impact on the capacity, quality and cost of operation. However, the formulation of a maintenance strategy depends on a number of factors, including the cost of down time, reliability characteristics and redundancy of assets. Consequently, the balance between preventive maintenance (PM) and corrective maintenance (CM) for minimising costs varies between organisations and assets. Nevertheless, there are some rules of thumb on the balance between PM and CM, such as the 80/20 rule.
Preventive maintenance is a type of proactive maintenance, while corrective maintenance is an example of reactive maintenance. Therefore, the answer should be "Balance between proactive maintenance and reactive maintenance".