1. 4 Requirements Definition Nick Lambrou HBS University of Westminster

2. 4 Requirements Definition ...a fleeting episode, a fragment of landscape or a remark overheard may provide the only means of understanding and interpreting areas which would otherwise remain barren of meaning. (C. Levi-Strauss, Tristes Tropiques)

3. 4 Requirements Definition Requirements Definition is probably the most important technique in any computer information systems development. It also is one of the least pictorial, making it difficult to describe precisely.

4. 4 Requirements Definition In essence, the technique involves capturing what the users really want and making sure that every subsequent project activity leads to the best possible transformation of those user needs into system needs which, when satisfied, will deliver what the users wanted in the first place.

5. 4 Requirements Definition Requirements Definition is the only technique that permeates every step of analysis and design.

6. 4 Requirements Definition • Requirements Catalogue • Finding the System Requirements • Types of Requirement • Requirements Definition Through the Salon Case Study

7. Figure 4.1 A blank Requirements Catalogue Entry suggestion

8. Types of Requirement • Requirements that simply retain the current environment’s functionality by reproducing what is already done in the business

9. Types of Requirement • Requirements where the same information as currently will be collected, but this time due to computerisation new opportunities arise in searching through it.

10. Types of Requirement • Requirements that introduce new activities to the business and really change work conditions.

11. Requirements Definition Through the Salon Case Study It quickly becomes apparent that three subsystems coexist within the Salon:

12. Requirements Definition Through the Salon Case Study an Appointments system which is the main business of the Salon; a Personnel system which ensures the recruitment of staff and trainees; a Stock system which ensures there are sufficient products to use.

13. APPOINTMENTS REQUIREMENTS • Produce a personal customer report • Produce a report of daily takings • Set up an appointment for a customer • Keep customer records • Keep a record of all the skills attained by trainees • Arrange for (immediate) payment of appointments

14. APPOINTMENTS REQUIREMENTS • Keep a record of stock usage • Hold a record of allergies and reactions • Produce a report to show the income generated per employee • Add new treatments • Warn about employee unavailability and stock shortcomings • Sell products through the salon

15. PERSONNEL REQUIREMENTS • Update employee files • Record new salary scales • Keep training record of trainees • Arrange for payment of weekly salaries • Produce a weekly employee availability list

16. STOCK REQUIREMENTS • Reconcile supplier invoices with deliveries • Reconcile deliveries with orders • Register purchase orders • Record inter salon transfers • Provide a list of stock in hand

17. STOCK REQUIREMENTS • Record suppliers and their products • Record invoice payments • Warn about outstanding invoices • Produce a 'year end' invoice report for accounts • Record new salons in the chain (for transfer purposes)

18. Figure 4.2 An example Requirement Catalogue Entry