1. 1 Recent work in the area: Requirement-Driven Development of Distributed Applications Gregor v. Bochmann School of Information Technology and Engineering (SITE) University of Ottawa May 2, 2003

2. 2 Objectives of NSERC project XXX To develop the available notations for specifying requirements, such as Use Case Maps (UCM), UML Activity Diagrams and other scenario notations, by comparing their usefulness, proposing formalizations and improvements, and contributing to related standardization activities in ITU and OMG. XXX To develop innovative methods and tools that can be used for the development of correct and secure system design models from a given specification of the requirements, considering in particular the possibilities for automating certain parts of this design process. To develop innovative formal validation and verification methods and tools appropriate for this process. XXX To evaluate the notations, methods and tools by applying them to realistic examples of distributed systems, especially in the area of service development for Internet telephony, e-commerce, and standard protocols developed by the Internet Engineering Task Force (IETF).

3. 3 Previous work (1) Clear semantics for UML Activity Diagrams Early 90ies: Description of workflow models (work at CRIM with DMR); development of a language and a related performance simulation tool 2001 (work for DRM): comparison of DMR’s language with UML; proposal for a revision of Activity Diagrams (better graphical syntax, and clearer semantics based on Petri nets) Note: On the semantic level, UCMs and Activity Diagrams are very similar

4. 4 Previous work (2) Derivation of protocol specifications from Service specifications 1987 with Gotzhein: FSM model + concurrency 1996 with Kant: Lotos 2000 – 2003 with Yamaguchi (Osaka), El-Fakih: Petri nets First: free-choice Petri nets with predicates, including explicit variables Lately: general (predicate) Petri nets (where a token at a place may play the role of a variable) Derivation of test suites from specifications of distributed systems, fault models Construction of missing submodule from given global behavior and existing submodules

5. 5 Ongoing Work (1) Petri-SOAP: Combining Petri-net oriented protocol derivation with Web-Services protocol standards (Yongsheng Yang, Master student) Colored Petri nets have tokens that are “objects” Use of the Apache SOAP implementation environment (in Java) Develop schemes for Java-implementation of Petri-net concurrency and token exchange between different sites participating in the distributed service Prototype based on an example system: workers, projects to be performed, clients, resource and payment management

6. 6 Ongoing Work (2) Grid (OGSA) interface to a Jini-based system for user-controlled ligthpath provisioning (UCLP) for Canarie (Jun Chen, Master student) Exercise in using the OGSI environment to implement a SOAP interface between a UCLP client and server Study the incorporation of more sophisticated security features into the UCLP application

7. 7 Ongoing Work (3) Performance modeling (Fida Dankar, PhD student) Process algebra approach to performance modeling What are suitable performance comparison relations for compositional system design ?

8. 8 Ongoing Work (4) Submodule construction for software reuse and derivation of controllers (Bassel Daou, PhD student) Extending previous work in this area (using LTS and FSM models) to models including interaction parameters and variables

9. 9 Ongoing Work (5) Derivation of distributed designs from global requirement specifications (Jinzhi Xia, PhD student) Given: UML Activity Diagrams or UCMs After defining the system components and responsibilities, the specification of each component behavior should be obtained automatically Inspired from existing approaches to deriving protocols from service specifications

10. 10 Ongoing Work (6) Methods for Designing Internet Telephony Services with Fewer Feature Interactions (Ken Chan, Master student) Use SDL specification of the basic SIP protocol and various features to detect feature interactions by checking MSC service scenarios against the protocol specification Methods for facilitating problem detection and avoidance