1. QUALITY MANAGEMENT PRINCIPLES

2. Objectives 4 Understand usefulness of CASE tools 4 Types of CASE tools 4 Data flow diagrams (DFD)

3. CASE tools C - Computer A - Aided S - Software E - Engineering

4. CASE tools 4 Can be used in a “standalone” mode 4 True power achieved with –proper environment –correct integration routines –correct portability features

5. Types of CASE tools 4 Project planning & management tools 4 Risk analysis tools 4 Documentation tools

6. Other graphical and text-based tools 4 Data flow diagrams (DFD) 4 Data dictionary 4 Process specification

7. Why graphical tools? How to make tea (description) Take a mug of water and pour it in a vessel. Place the vessel on the gas stove and heat it. Let the water boil. Add 1 spoon sugar and 1 spoon tea leaves. Switch off the gas. Let the mixture stand for some time. Add ½ cup of milk. Taste the tea to check the sugar. In case more sugar is required, add more sugar. Taste the tea again. Repeat these steps until the tea is sweet enough. Pour the tea in a cup.

8. Why graphical tools? Heat water Add sugar & tea (1 spoon each) Is water boiling? No Yes Remove from heat and let stand

9. Why graphical tools? Add 1/2 cup milk Is tea sweet enough? Add more sugar No Pour tea in a cup Yes

10. Data flow diagrams(DFDs) A data flow diagram is a graphical technique that depicts information or data flow and the transforms that are applied as data move from input to output.

11. Top-down partitioning Context diagram Process 1.0 Output A Input A Input B Input C Output B

12. Top-down partitioning Level 1 DFD Process 1.1 Process 1.2 Input A Input B Input C Data flow Output A Output B

13. Remember! 4 DFD only indicates flow of data and not sequence of events 4 Balancing of inputs and outputs is essential while partitioning DFDs 4 System behaviour not understood through DFDs