The reduction of stock level that most firms have performed has brought immediate financial economy results, but has caused an exponential growth of the number of purchase orders and supplying processes and consequently an explosion of the related costs. Considering equal facilities, the efficiency of the internal services is therefore seriously compromised. Moreover, the fast pace of progress and the constant employment of new technologies has lead to having to deal with an ever-increasing number of suppliers.

Proportioning costs to needs in order for the relation between cost and efficiency of structures to be direct and measurable. This is today possible by transforming the least profitable, but proportionally more expensive part of the internal supplying process, into services to be purchased on the market. This way there is an immediate transformation of fixed costs into variable costs that will follow the firm's trend.