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 4Slide 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