• If the objective is to avoid surpluses or shortages of stock, calculation of quantities needed should be based on past consumption. If the objective is to assess the amounts strictly required for priority needs, quantification should be based on morbidity and treatment schedules. In the latter case, it should be closely linked with a programme for the rational use of drugs.

As these two methods of quantification give different results, the ideal is to use them together in order to purchase exactly what will be consumed and ensure that only the quantities strictly required are consumed. This avoids simply repeating past practices, and it recognizes constraints due to the behaviour of distributors and prescribers. In practice, quantification should be determined by the information available and the stage of development of the supply services.

• The centralization of procurement reduces transaction costs to a minimum and concentrates skills, laying the basis for a procurement strategy that works well. Centralization does not necessarily lead to a monopoly; a duopoly or an oligopoly may be preferable.

• Control of procurement is necessary but control of a procurement body and its personnel should not be exclusively legal and administrative because the most effective strategy cannot be fully encompassed in a formal definition. There must also be political or organizational controls.