Return to the Evolution Tree Model Baseline(基线)：At the end of each episode,a complete set of artifacts(组件) Baseline at the end of Episode 4: Requirements3,Analysis3,Design4,Implementation4 ◆ Development Maintenance Requirements Requirements3 Analysis1 Analysis3 Design1 Design3 Design4 Implementation Implementation2 Implementation3 Implementation4 Episode 1 Episode 2 Episode 3 Episode 4
Slide 2.11 11/50 Return to the Evolution Tree Model Baseline(基线)： At the end of each episode , a complete set of artifacts (组件) Baseline at the end of Episode 4: – Requirements3 , Analysis3 , Design4 , Implementation4
Chapter Overview Information System Development in Theory理论上的信息系统开发 Winburg Mini Case Study一个小型案例研究 Lessons of the Winburg Mini Case Study这个小型案例研 究的教训 Teal Tractors Mini Case Study第二个小型案例研究 Iteration and Incrementation迭代和增量 Iteration:The Newton-Raphson Algorithm迭代：牛顿拉普森算法 The Winburg Mini Case Study Revisited再次探讨第二个小型案例 Other Aspects of Iteration and Incrementation迭代和增量的其他方面 Managing Iteration and Incrementation管理迭代和增量 Maintenance Revisited再论维护
Slide 2.12 12/50 Chapter Overview Information System Development in Theory 理论上的信息系统开发 Winburg Mini Case Study 一个小型案例研究 Lessons of the Winburg Mini Case Study 这个小型案例研 究的教训 Teal Tractors Mini Case Study 第二个小型案例研究 Iteration and Incrementation 迭代和增量 Iteration: The Newton–Raphson Algorithm 迭代: 牛顿-拉普森算法 The Winburg Mini Case Study Revisited 再次探讨第二个小型案例 Other Aspects of Iteration and Incrementation 迭代和增量的其他方面 Managing Iteration and Incrementation 管理迭代和增量 Maintenance Revisited 再论维护
Lessons of the Winburg Mini Case Study In the real world,Changes are always needed The real world is continually changing Information technology professionals are human,so we make mistakes Man cannot escape mistakes Faults must be fixed quickly If not,it will be carried over into the next phase -60~70%of all detected faults are requirements, analysis,and design faults
Slide 2.13 13/50 Lessons of the Winburg Mini Case Study In the real world, Changes are always needed – The real world is continually changing – Information technology professionals are human, so we make mistakes Man cannot escape mistakes Faults must be fixed quickly – If not, it will be carried over into the next phase – 60 ~ 70% of all detected faults are requirements, analysis, and design faults
Relative Cost to Detect and Correct a Fault 368 350 300 pue 250 200 150 100 52 50 3 4 Requirements Analysis Design Implemen- Maintenance phase phase phase tation phase phase
Slide 2.14 14/50 Relative Cost to Detect and Correct a Fault
Chapter Overview Information System Development in Theory理论上的信息系统开发 Winburg Mini Case Study一个小型案例研究 Lessons of the Winburg Mini Case Study这个小型案例研究的教训 Teal Tractors Mini Case Study第二个小型案例研究 Iteration and Incrementation迭代和增量 Iteration:The Newton-Raphson Algorithm迭代：牛顿拉普森算法 The Winburg Mini Case Study Revisited再次探讨第二个小型案例 Other Aspects of Iteration and Incrementation迭代和增量的其他方面 Managing Iteration and Incrementation管理迭代和增量 Maintenance Revisited再论维护
Slide 2.15 15/50 Chapter Overview Information System Development in Theory 理论上的信息系统开发 Winburg Mini Case Study 一个小型案例研究 Lessons of the Winburg Mini Case Study 这个小型案例研究的教训 Teal Tractors Mini Case Study 第二个小型案例研究 Iteration and Incrementation 迭代和增量 Iteration: The Newton–Raphson Algorithm 迭代: 牛顿-拉普森算法 The Winburg Mini Case Study Revisited 再次探讨第二个小型案例 Other Aspects of Iteration and Incrementation 迭代和增量的其他方面 Managing Iteration and Incrementation 管理迭代和增量 Maintenance Revisited 再论维护