IGCSE ICT

1. IGCSE ICT Stock Control

2. The syllabus says you must: • Understand the need for and use of automated stock control systems • Be able to discuss the advantages and disadvantages of automated stock control systems • Understand the role of the check digit as a form of validation

3. Stock control : the old way • Price labels were handwritten and stuck on manually • Staff/time/cost • Labels could be misread/changed • Yearly stock-check: closed for business

4. The problems • Slow • Costly • Required many staff • Impact on revenue • Accuracy? • Lost revenue through wrong or misread labels • Lost revenue through stock-taking closures • Stock control done by guesswork

5. The technology behind ASCS • ASCS rely on barcodes • Barcodes allow quick identification of product details when the barcode is scanned • The barcode reader scans the barcode using a laser • It retrieves the price and the details from the database

6. What’s in a bar code? 1 • Bar codes are made of alternating dark and light lines of varying thickness

7. What’s in a bar code? 2 • The barcode contains data about the type of product, size, manufacturer and the country of origin. • It also contains a check digit, so that the computer can validate that the data has been read in correctly.

8. What’s in a bar code? 3 • The barcode does not contain price. The price is held in the database instead. • This makes it easy to change if there are special offers or prices go up. Imagine if the price was part of the barcode. Every time the price changed, you would have to replace all of the packaging.

9. What’s in a bar code? 4 • Once the barcode has been recognized by the database and the price found, the data is sent from the central computer to the till (Electronic Point of Sale - EPOS).

10. The check digit • The check digit is a form of validation • It is used to ensure no errors occurred when the barcode was read in • There are a number of ways of calculating check digits depending on how many digits there are in the barcode

11. 1 1 3 4 5 1 7 2 9 1 11 odd digit positions 5 1 0 4 3 1 1 2 0 1 7 2 1 4 4 6 1 88 10 even digit positions This method works for codes with 11 digits: Add the digits in the odd positions, multiply by 3 (5+0+3+1+0+7=16 16x3=48) • Add the digits in the even position: 1+4+1+2+1=9 • Add the two together: 48 + 9 = 57 • Check digit is 3 (needs to be added to make next multiple of 10). Checked every time a bar is scanned!

12. Where are bar codes used? • Library book systems • Administration systems (eg hospitals) • Passport & ID card systems • Equipment checking systems (eg fire extinguishers) • Automatic stock control systems

13. Sequence of events 1 • Barcodes on all items: each is associated with a stock file holding details of price, stock level, description etc. • Customer goes to checkout: barcodes scanned • Stock file is searched, record by record, until a match is found • Appropriate record is accessed • Price & description sent to EPOS • Stock level reduced by 1: new stock level written to file

14. Sequence of events 2 • If new stock level is = or 1 less than re-order quantity, new batch is automatically ordered • Flag assigned to item to indicate order (stops re-order being made for EVERY purchase!) • This is repeated for every item in basket/trolley • Itemized bill given to customer • Loyalty card updated/takings file updated • Barcodes on cartons of new goods used to update stock file & flags removed

15. Advantages Accuracy Speed Optimum stock levels Patient safety Equipment safety Analysis Automatic re-ordering Automatic scheduling of updates etc Disadvantages Cost Training Over-reliance on technology Advantages & Disadvantages

16. Download the file Electronic Fund Transfer Simulation Enter some purchases and look carefully at the following: Banking/EFTPOS data Stock levels Receipt Today’s assignment:

17. Homework • Read the information at http://communication.howstuffworks.com/how-inventory-management-systems-work.htm • Go to www.edmodo.com and complete the homework assignment.