Determining availability targets — A value managerial approach

A method is proposed which allows to determine availability targets by means of a value managerial approach. It balances customer requirements related to the given product with a limited budget assigned to assure availability. Thereby, the product's functions' importance are the driving determinant of the availability level desired by the customer, constraint by the assigned availability budget. The trade-off between customer satisfaction regarding the availability of a (sub-) system and budgetary constraints stemming from the manufacturer is found systematically — with the product's functions in the focal point. Each subsystem's target availability level is found in accordance with its quantitative contribution to fulfilling the functions as desired by the customer. The availability (maintenance) budget is methodically broken down and allocated to each subsystem purposefully in line with their contribution to availability in order to achieve the utmost customer satisfaction. The availability is concluded upon by bringing together such budgets per subsystem and their maintenance costs referenced to hours of downtime. The thus obtained subsystems' targets are used to determine the system's availability target in line with the system's availability structure. By contrast with most existing methods this weakens the dependence on empirically determined factors to apportion availability top-down significantly. Decisions on a financially optimal availability strategy concerning the degree of redundancy can thus be substantialized. Methods aiding to determine the actual degree of redundancy are not part of this paper however. Since availability is not only composed of criteria which product development can directly influence, an adequately matching business model needs to go along with these targets. Coupling similarly found reliability targets with the hereby found availability targets may help to substantialize strategic decisions related to reliability and availability and their trade-off [1], directly influencing customer satisfaction and ultimately economic success.