The maintenance control function can be viewed as an important and integral part of the maintenance management function (MMF). The MMF consists of planning, organizing, leading and controlling maintenance activities (Schermehorn, 2007). The planning function develops objectives and targets to be achieved. In the case of maintenance the targets could be measures regarding availability, quality rates and production. Then management organizes, provides resources and leads to perform tasks and accomplish targets. The implementation of the plans are undertaken to accomplish intended objectives. The fourth function of maintenance management is controlling which concerns monitoring, measuring performance, assessing whether objectives are met and taking necessary corrective actions if needed. Figure 5.2 depicts the management function, its sub-functions and their interactions.