The type and quantity of drug to be ordered will depend on the disease pattern of the area served by the health centre, the quantity for each dosage form previously consumed, when drugs were not out of stock, the period for which the new stock is to serve and the number of patients. In determining the quantity to be requested:
• Consider the lead or delivery time.
• Consider the number of patients to be treated (using national treatment guidelines).
• Collaborate with the head of the health centre (prescriber) when making a new request. The prescriber is better placed to know for which item an extra quantity has to be requested because of epidemics or seasonal changes in disease pattern.
• Look through all the stock cards in a systematic manner and compare the RI with the current stock balances.
• Request only those items where the stock balance approaches the RI, equals the RI or is below the RI.
(a.) RI = 6 tins; Balance: 8 tins (number of patients = 100)
(b.) RI = 6 tins; Balance: 6 tins (number of patients = 100)
(c.) RI = 6 tins; Balance: 0 tins (number of patients = 100)
In the above three situations, consider the existing lead time of three months and add one month as RESERVE for unforeseen circumstances such as delay in deliver y, breakdown of delivery vehicle, stock rupture at the central store, bad roads, unforeseen epidemic and so on.
(a.) RI = -6 tins; current stock balance = 8 tins
In this case the RI is above by 2 tins.
Therefore, make the normal request less by 2 tins
Request quantity = 2 tins × 3 months + 1 month consumption (2 tins)
= (2 × 3) + 2 - 2
= 6 tins
(b.) RI = 6 tins; current stock balance = 6 tins
Average monthly consumption is 6 tins/3 = 2 tins
The quantity to be ordered is:
Average monthly consumption × Lead time + 1 month consumption for unforeseen events
= (2 tins × 3 months) + 2 tins
= 8 tins
(c.) RI = 6 tins; current stock balance = 0 tins
In this case an extra quantity must be requested to cover the RI.
Request quantity = 2 tins × 3 months + 1 month consumption (2 tins) + RI (6 tins) quantity
= (2 × 3) + 2 + 6
= 14 tins
In each case above, if previous data show that the number of patients would increase (e.g. malaria cases due to seasonal variations), then the quantities should be increased proportionally.
If the number of patients is expected to double, then the quantity should be multiplied by 2.
If the number of patients is expected to drop by half, then the quantity should be multiplied by 1/2.