Synthesizing Component-Level Behavior Models from Scenarios and Constraints

1. Synthesizing Component-Level Behavior Models from Scenarios and Constraints Ivo Krka

2. Motivation • Early development phases • Scenarios • Properties / Constraints • Partial but straightforward • Synthesizing behavior models from high-level specifications • Statecharts, LTSs • Architectural analysis • Basis for subsequent development phases • Final models do not account for partiality • How to support gradual system refinement?

3. Web Cache System

4. Cache’s Behavior S0 S1 S2 S3 requestCacheData requestServerData responseServerData responseCacheData responseCacheData S5 S6 S4 responseCacheData requestCacheData What else can occur?

5. Modal Transition Systems • Modal Transition Systems • Specify what is required • Specify what is potential A S0 S1 B? A B A? S2

6. Partial Behavior Models • Proven useful • Exploration of design space • Requirements elicitation • Architectural refinement • System-level model issues • Scale • System-level assumptions • Solution? • Synthesize Component-Level Models

7. Synthesis Phases • Obtain component-level constraints • Generate initial MTSs • Annotate sequence diagrams • Refine initial MTSs

8. Web Cache System (2) requestServerData? responseServerData? requestServerData responseServerData requestCacheData S0 S1 S2 S3 responseCacheData responseServerData? responseServerData? responseCacheData S4 S5 requestCacheData responseServerData?

9. Conclusions and Future Work • Early discovery of design flaws • Overly constraining constraints • Bad scenarios • Lacking design • System vs. component view • Future work • Realistic case studies • Support for requirements elicitation • Support in OTS component selection

10. Thank you!