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World Journal Control Science and Engineering. 2013, 1(1), 25-34
DOI: 10.12691/wjcse-1-1-4
Open AccessArticle

Cost Optimization of Maintenance Scheduling for Wind Turbine Gearbox Components with Assured Reliability

Shawki A. Abouel-seoud1 and Mohamed I. Khalil1,

1Automotive Engineering Department, Helwan University, Cairo, Egypt

Pub. Date: November 12, 2013

Cite this paper:
Shawki A. Abouel-seoud and Mohamed I. Khalil. Cost Optimization of Maintenance Scheduling for Wind Turbine Gearbox Components with Assured Reliability. World Journal Control Science and Engineering. 2013; 1(1):25-34. doi: 10.12691/wjcse-1-1-4


The operation of a particular component in deteriorating condition will lead to a high machine downtime. This is due to the failure of component at unexpected time. As a result it will increase cost of maintenance and production lost. One of the solutions to this matter is to use Preventive Replacement (PR). PR is one of the maintenance optimization strategies that can balance the failure cost in unexpected time (maintenance and production lost) and maintenance benefits (minimize downtime) for a deteriorating component. Therefore, the objective of this paper is to introduce the PR strategy for determining an optimal replacement time for component that deteriorates over time. The models are used for the cost per unit time based on the stochastic behavior of the assumed system. The model reflects the cost of storing a spare as well as the cost of system downtime. The minimum-cost (optimum) policy time is calculated with the consideration of availability. It is noted that all maintenance cost results converge to the optimal value of the age replacement policy which has the same configuration when inspection interval increases.

maintenance preventive maintenance availability limit maintenance cost optimization replacement policy

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[1]  Wang, W. “A model to determine the optimal critical level and the monitoring intervals in condition-based maintenance,” International. Journal of Production Research, Vol. 38, No. 6, pp. 1425-1436, 2000.
[2]  Yang, Y. and Klutke, G.-A. “Lifetime-characteristics and inspections schemes for Lévy degradation processes,” IEEE Trans. Reliability, Vol. 49, pp. 377-382, Dec. 2000.
[3]  Lin, D., Wiseman, M., Banjevic, D. and Jardine, A. S. " An approach to signal processing and condition-based maintenance for gearboxes subject to tooth failure" Mechanical Systems and Signal Processing 18, pp. 993-1007, 2004.
[4]  Tian, Z., Jin, T. Wu, B. and Ding, F. "Condition based maintenance optimization for wind wind power generation systems under continuous monitoring" Renewable Energy36, pp. 1502-1509, 2011.
[5]  Martinez, E., Sanz F and Pellegrini S. "Life cycle assessment of a multi-megawatt wind Turbine" Renewable Energy 2009 34(3), pp. 667-673, 2009.
[6]  Biswas, A. and Sarkar, J. "Availability of a system maintained through several Imperfect repairs before a replacement or a perfect repair" Statistics and Probability Letters 50,pp. 105-114, 2000.
[7]  Klutke, G. A. and Yang, Y. J. "The availability of inspected systems subjected to shacks and graceful degradation" IEEE Transaction on Reliability" 51, pp. 423-430, 2002.
[8]  Stevens, B. "EXAKT reduces failures at Canadian Kraft Mill" ( , 2006.
[9]  Abouel-seoud, S. A., Khalil, M. I. and El-morsy, M. S. "Optimization of gearbox replacement policy using vibration measurement data" International Journal of Vehicle Noise and Vibration, Vol. 8, No. 4, December 2012.
[10]  Abouel-Seoud, S. A., Elmorsy, M. and Ahmed Saad, A. " A Laboratory Apparatus for Investigation of Vibration Performance of Wind Turbine Planetary Gearbox" International Journal of Current Research,Vol. 3, Issue, 12, pp.214-219, 2011.
[11]  El-morsy, M. S., Abouel-seoud, S. A. and Rabeih, A." Gearbox Damage Diagnosis using Wavelet Transform Technique" International Journal of Acoustics and Vibration, Vol. 16, No. 4, pp. 173-179, 2011.
[12]  Jardine, A.K.S., Lin,D. M. and Banjevic, D." A review on machinery diagnostics and prognostics implementing condition-based maintenance" Mechanical Systems and Signal Processing 20(7). Pp. 1483-14510, 2006.
[13]  Cammpbell, J. and Jardine, A.K." Maintenance Excellence" Marcel Dekker Inc., New York, USA, ISBN 0-8247-0497-5, 2001.
[14]  John, D. "The Reliability of Mechanical Systems , Mechanical Engineering Publications Limited for The Institution of Mechanical Engineers, London, 1988.
[15]  Barringer, H. P. "Availability, Reliability, Maintainability and Capability" Triplex Chapter of the Vibrationa Institute, Hilton Hotel-Beaumont, Texas, February 18, 1997.
[16]  Grant, I. W., Clyde F. and Coombs, Jr., Richard Y. Moss " Handbook of Reliability Engineering and Management" 2nd edition, McGraw-Hill, 1996.