Journal of Systems Engineering and Electronics ›› 2011, Vol. 22 ›› Issue (5): 788-793.doi: 10.3969/j.issn.1004-4132.2011.05.010

• SYSTEMS ENGINEERING • Previous Articles     Next Articles

Optimal maintenance decisions for gamma deteriorating systems

Lin Tan1,*, Chiming Guo2, Zhijun Cheng2, and Bo Guo2   

  1. 1. Department of Human Sciences, College of Humanities and Social Sciences, National University of Defense Technology, Changsha 410074, P. R. China;
    2. Department of Systems Engineering, College of Information System and Management, National University of Defense Technology, Changsha 410073, P. R. China
  • Online:2011-10-28 Published:2010-01-03


An optimal replacement model for gamma deteriorating systems is studied. This methodology uses a gamma distribution to model the material degradation, and the impact of imperfect maintenance actions on the system reliability is investigated. The state of a degrading system immediately after the imperfect maintenance action is assumed as a random variable and the maintenance time follows a geometric process. A maintenance policy (N) is applied by which the system will be repaired whenever it experiences Nth preventive maintenance (PM), and an optimal policy (N*) could be determined numerically or analytically for minimizing the long-run average cost per unit time. Finally, a numerical example is presented to demonstrate the use of this policy.