Decision theory in maintenance strategy for a 2-unit redundant standby system

Obtaining a good maintenance strategy for a standby system is discussed. The problem is analyzed via decision theory to determine the waiting time to call the repair facility (for a two-unit standby system) when the first piece of equipment fails. Previous research into this kind of system is briefly described, and a need for constructing a decision model is explained. The uncertainty of the parameters is accounted for in a Bayes approach in order to consider expert prior knowledge. The failure and repair rates are assumed to be constant and are elicited from an expert´s prior beliefs. When no data are available, expert guesses are used. A method is presented for solving the conflicting requirements of system availability and cost through a multiattribute utility function which can express cardinal values for the decision maker´s preferences over the objective variables. The decision model derives the appropriate maintenance strategy; it corresponds to a set of actions, procedures, and resources, giving a consequent waiting time before calling the repair facility. The use of the model is demonstrated for a telecommunication system