Optimale revisietijd

Optimum period of overhaul, a case-study
A general formula is given, when to proceed to an overhaul in such a way that the costs of wear and those of overhaul together will be a minimum (par. 2). In par. 3 the practical solution for cells in electrolysis is discussed. First a nonstochastic model is considered, then the more realistic stochastic model. It is proved that an overhaul is not indicated after a certain space of time or after a certain increase in the costs, but when a certain absolute level of the costs (corresponding with a certain electrical tension) is reached irrespective of what went before. A formula (14) to this end is given. Attention is also paid to the problem of the numerical evaluation.