Decreasing capacity utilization rates and financial constraints are reasons for the ongoing performance improvements of cement plants. O&M contracts can be the solution to achieve these objectives when technical solutions are getting more complex and when operational know-how is limited. This article will look at this approach more closely. Cement plants differ in plant age, size, technology, automation, fuel supply, operational and maintenance requirements and other issues. More CapEx is spent on the latest technology, to reduce operational and maintenance costs. Sometimes it is very difficult to compare individual plants. Plants with several kiln lines, which use identical raw materials, can compare the efficiency of the individual kiln lines more effectively than an isolated plant with one kiln line.