Supermarket : Stock Check

The stock level field in the stock database stores a record of how many units of a particular item should be in stock at the current time. This level is adjusted automatically :

However stock can sometimes be added or removed from the supermarket without this being recorded on the database. For example :

Reason Explanation
Theft An item could be stolen from the store. This would be removed from the stock, but the database stock level would not be decreased.
Checkout Operator Error When goods are sold they are removed from the stock database as their barcodes are scanned. If a customer purchased a large number of items then the checkout operator could easily forget to scan one of the items by mistake. The missed item would be removed from the stock, but the database stock level would not be decreased.
Delivery Error The person who accepts the delivery of new items at a store could accidently record the number of items or type of items that have been delivered incorrectly.

The effect of these errors would be that the actual stock level is not the same as the stock level in the database. If the actual stock level was below the stock level in the database then the store could run out of an item before it was reordered.

To reduce the likelihood of this happening a stock check will be carried out periodically. A stock check means that the items that the supermarket sells are counted and the actual stock level of each item is compared to the stock level in the database. If the two do not match then the stock level in the database will be changed to the actual stock level.

It takes a lot of work by members of staff to carry out a complete stock check so this is not done very often, if ever. However stock checks on a small range of items within a store will be carried out regularly.

The Stock Check Device

Stock checks are carried out by a person using a small handheld computer with a built in barcode scanner, keyboard and Liquid Crystal Display (LCD). The computer contains some RAM which is used to store a copy of the information about some of the products, taken from the stock database. The stock check process works like this :

1.  Before the stock check takes place the information about the products to be checked is copied from the stock database into the RAM in the handheld computer.
 
2.  For each item that is to be checked :
  • The member of staff scans the barcode on the item that he is counting.
  • The computer displays the name of the item and how many units should be in stock, according to the stock database.
  • The member of staff counts how many units of the item are actually on the shelf.
  • The number of units that are actually on the shelf is typed on a keyboard and the stock level stored in the handheld computer is changed to the real stock level, if they differ.
 
3.  After all of the items have been checked, the handheld computer is connected to the computer storing the stock database and the stock levels on the database are updated.

Any significant differences between the expected and actual stock level will be noted by the computer so that the reasons for them can be investigated.

The handheld computer that is used to collect the information about stock levels is sometimes known as a data logger.

GCSE ICT Companion 04 - (C) P Meakin 2004