The model of a procurement process taking into account the consequences of a technical system unreliability

The paper concentrates on the problem of a technical system spares back-up, when spares are critical for the system availability. The delivery moment can not be forecasted precisely and possible delays may cause unwanted (even severe) consequences for the system. When the system has a particular reliability structure, the procurement process has to react to this fact because the same process parameters will cause different results. The approach proposed takes into account two points of view of the problem: the system availability effects and economic aspects of its procurement. The created simulation model investigates the parameters of the procurement process (order quantity, critical inventory level, lead-time length) and allows to find the best solutions of the spares back-up process.