1. 1 Using Interaction matrices for requirements analysis Objective – to discover the interactions between requirements and to highlight requirements conflicts and overlaps. Tool – spreadsheet Rows – label the requirement identifiers in ascending order Columns – label the requirement identifiers also in ascending order Each requirement is then considered and compared with other requirements. You then fill in values in the spreadsheet cells as follows: 1.If conflict, fill in 1 2.If overlap, fill in a 1000 3.If independent, fill in a 0

2. 2 Situations: If you cannot decide whether requirement conflict, assume yes Why? Interaction matrices example RequirementR1R2R3R4R5R6 R1001000011 R2000000 R3100000 0 R4001000011 R5100100 R6101000100 R1 overlaps R3 R1 conflicts with R5 and R6 R2 is an independent requirement R3 overlaps with R4 and R6 …

3. 3 Number of conflicts = 3000 % 1000 = 0 Number of overlaps = (int) 3000 / 1000 = 3 A large number of conflicts or overlaps means that any changes to that requirement will probably have a major impact on the rest of the system. RequirementR1R2R3R4R5R6 R1001000011 R2000000 R3100000 0 R4001000011 R5100100 R6101000100 10020300010022

4. 4 Requirements Analysis and Negotiation Video game minimum system requirements R1. Video card memory shall be at least 256M R2. Video card memory speed shall be at least 800MHz R3. Video card interface type shall be AGP R4. The video game shall be installed in 32-bit architecture system. R5. Monitor resolution shall be at least 1024x768pixel R6. Motherboard video card slot shall be PCIe R7. Input device shall be a three-button mouse and ANSI 108-Key keyboard R8. CPU speed shall be at least 1G Hz R9. The operating system shall be at least Windows 95. Exercise

5. 5 Where are we? Next class – Validation