Rise Sics

Optimized Gas Turbine Maintenance

Condition-based maintenance often involves measuring operational parameters and estimating remaining lifetimes of critical industrial equipment. SICS has spent 2007 and 2008 developing maintenance planning software for Siemens Industrial Turbomachinery AB in Finspång, Sweden, a leading manufacturer of gas turbines. The software is used to reduce maintenance and downtime costs by optimizing maintenance plans. Optimization is based on downtime reductions due to the joint allocation of maintenance activities, and the scheduling of time-consuming activities to the calendar periods when the costs of lost production are as low as possible.

In addition, the planning software can be used dynamically to re-plan maintenance as soon as new information is available for example, when updated lifetime predictions from changes in the operational plan are to hand. Dynamic maintenance planning of this nature can yield substantial cost reductions in the form of higher availability and lower maintenance costs.

The software is currently being used for gas turbine maintenanceplanning with lifetime predictions done by Siemens. Calculations show a possible increase in availability of 0.5 to 1 %, which is a significant improvement.

Even when better lifetime predictions are not available and maintenance intervals are kept to the same length as before, significant reductions in preventive maintenance downtime are possible. According to Siemens, downtime reductions of approximately 12 %, due only to improved planning of preventive maintenance activities, can be expected in the general case. In a case study performed at SICS with lifetime data from Siemens, downtime due to preventive maintenance could be reduced even more.