The high cost for maintenance and support often comes together with poor operational system performance. This situation seems to result from the lack of integration between system design and the logistic support system leading to forced compromises between what can be afforded and what can be tolerated.

To prevent this from happening, the interaction between system design and logistics alternatives must be studied as part of the decision process whereby options to correct gradually will be closed. In practice, this requires a convenient and versatile way to model alternatives and analyse what cost/performance relations could be achieved, at best, depending on choices made. This task implies a capability to combine detailed modelling with cost/performance analysis and optimisation. OPUS10^TM is the latest version, developed as part of several hundred actual system design projects, over a period of more than 30 years, to fill this need.

In OPUS10^TM an operational scenario with sites (stores, depots, workshops etc.), systems and utilisation profiles are modelled to establish a joint pattern of demand for logistics support. Maintenance and logistics activities are also modelled with reference to the detailed breakdown of systems. An optimal set of spares is then allocated to the logistics structure to offset time effects of logistics activities as needed to support different availability performance levels. In this sense, OPUS10^TM provides the user with the 'best possible' relationship between effectiveness and cost given all the detailed parameters for system design and the logistics support system.

Even if OPUS10^TM primarily is a tool for the analysis of logistics and systems alternatives, its ability to optimise the allocation of spares in a given operational and logistics environment make it a powerful provisioning tool. In this latter role, it is most often used to optimise the assortment and allocation of expensive spares e.g. repairables or discardables with a significant effect on system availability and total cost of ownership. For routine provisioning of non-expensive parts carried in large numbers, OPUS10^TM analysis can be done either in a more general way or as detailed as the user wants.