During the past decades widespread mechanization and automation has reduced the number of production personnel while capital employed in production equipment has increased. Therefore, the importance of the maintenance function and of maintenance management has grown. The widespread mechanization and automation has reduced the number of production personnel and increased the capital employed in the production assets. As a result, the fraction of employees working in the area of maintenance as well as the fraction of maintenance spending on the total operational costs has grown over the years. It is not uncommon that the maintenance and operations departments the same size. The maintenance costs can be the largest part of any operational budget. The main issue faced by the maintenance management, whether its output is produced more effectively, in terms of contribution to company profits and efficiently, in terms of manpower and materials employed.