in order to improve economic benefits, reduce costs and reduce capital possession, the daily purchase quantity should be determined according to the principle of diligence and quick sales and the principle of single purchase.

determination of the purchase quantity of fresh food raw materials

This kind of food raw materials are generally easy to deteriorate and cannot last forever. After purchase, they can only be used in a short time. The quantity of each purchase can be determined according to the following formula:

Quantity to be purchased = quantity to be used-quantity on hand

Determination of the purchase quantity of dry food raw materials

1. Regular ordering method

Regular ordering method is a kind of fixed ordering cycle. Every order date, the warehouse manager makes an inventory of the warehouse and then decides the order quantity. The formula is as follows: demand for the next period-quantity on hand+quantity on hand at the end of the period = order quantity

Example:

A restaurant needs to order canned pineapples once a month, with an average consumption of 11 cans per day, and the order period is four days, that is, the delivery date is the fourth day after the order date. The warehouse keeper found that there were still 51 cans of pineapples in stock through inventory.

based on the above information, the purchase quantity can be determined. However, in fact, the determination of the final demand stock is not ideal 4 X 11. Considering the unexpected reasons such as transportation, weather or supply, many restaurants add an insurance reserve to the final demand stock to prevent accidents. This insurance reserve is generally 51% of the theoretical end-of-term demand, so the end-of-term demand actually becomes:

end-of-term demand = (average daily consumption x days of order period) X 151%

If the above example is still calculated, the order quantity is:

order quantity =(31 X 11)-51+(11 x 4) x 151% = It is an inventory control method that keeps a continuous record of all incoming and outgoing materials, and guides procurement through a perpetual inventory table. However, because this method needs professionals to record fairly accurate digital records, there are not many enterprises that adopt perpetual inventory method, and only large catering enterprises, especially those big hotels run by groups, will use this method.

Example:

A restaurant orders canned pineapple slices once every two months, with an average daily consumption of 11 cans, the ordering period is 4 days, the maximum reserve is 151 cans, and the reorder point is 61 cans. On February 1, when the warehouse keeper found that 11 cans were sent out, there were 61 cans left, which had reached the reorder point. So an order notice was issued, and the order number was #637-43. The order quantity was still calculated according to the formula mentioned above. The maximum reserve is the demand for the next period, and the number of reorder points has actually taken into account the insurance factor, so the order quantity should be:

151-61+11×4=131 (cans)

Considering that boxes are the purchasing unit, we should actually order 11 boxes, that is, 132 cans, so that after four days, the goods arrive and the inventory will increase to 151 cans.

economic order lot size model (EOQ model)

Starting point and assumptions of EOQ model:

(1)EOQ model involves two kinds of expenses, one is purchasing expenses, and the other is storage expenses.

(2) Purchasing expenses refer to the order fee, telex or telephone fee, acceptance fee, etc. required for each purchase. This part of the cost has nothing to do with the size of the batch and should be regarded as a fixed cost.

(3) storage costs. Storage fees, insurance fees, labor costs, site occupation fees, etc. arising from inventory.

since the storage cost depends on the inventory, it should be regarded as variable cost.

for the convenience of calculation, we assume that:

Q= economic order quantity;

F= the cost of each purchase;

D= annual demand of a certain raw material;

C= storage cost of unit raw materials;

TC= total annual purchase and storage expenses.