Evaluation of maintenance policies for equipment subject to quality shifts and failures

Sofia Panagiotidou (1) , George Tagaras (2)

1 Department of Mechanical Engineering
2 Department of Mechanical Engineering

We develop an economic model for the optimization of maintenance procedures in a production process with two quality states. In addition to deteriorating with age, the equipment may experience a jump to an out-of-control state (quality shift), which is characterized by lower production revenues and higher tendency to failure. The times to quality shift and failure are allowed to be generally distributed random variables. We consider two types of maintenance: minimal maintenance (MM) that upgrades the quality state of the equipment without affecting its age and perfect preventive maintenance (PM) that fully upgrades the equipment to the as-good-as-new condition. We derive the expression for the expected profit per time unit and we investigate, through a large number of numerical examples, the type of the optimal solution. It is concluded that in practically every case the optimal maintenance policy is an extreme one: it either calls for immediate MM as soon as a quality shift occurs (active policy) or it allows operation in the out-of-control state until the time of a scheduled PM action (passive policy).

Mots clés: Physical Sciences

Sofia Panagiotidou, George Tagaras. Evaluation of maintenance policies for equipment subject to quality shifts and failures. International Journal of Production Research, 2008, 46 (20), pp.5761-5779. ⟨10.1080/00207540601182260⟩. ⟨hal-00512971⟩