Operational (operations) research
This concerns the development of procedures in the various disciplines that coexist within industry with the object of maximizing efficiency in the use of resources and time available. It is necessarily much concerned with management techniques and is, to this extent, a tool of management. A fair example of ends to which such research is directed lies in the precise control of stock levels. This includes ^ minimum quantities and schedules relating I to both the time and quantity of repurchasing, geared to various levels of output.
Reference: The Penguin Business Dictionary , 3rd edt.