do u know anything about stock control?

the majority of stock control systems would be the same.

There would be a Par stock limit for each item. Once you fall be low the limit you re order the product back up to its maximum limit. This upper and lower limit is set depending on the demand the the item.

As new stock arrives the older stock is brought forward with the new stock placed behind. there are 2 terms for this that mean the same. FIFO (First in First Out) or LILO(Last In Last Out). This is done so that expiry dates are not reached.

Once a month you count the stock that you have. then you work out how much you have sold and also make a note of how much you started with. This is called a stock take and will tell you whether you have a surplus or deficit in stock. If you do then you need to tighten your controls on who handles and records the stock especically with pharmecuticals.

it would be a pos(point of sale/till) based inventory management sytem which would calculate what stock you should have left after selling the through the tills then you would stock take manually and the computer would calculate what you have counted against what it has worked out should be there and you are left with the difference +/-