About

Cashew logo colour

The Cashew project focused on the description and composition of semantic web services, emphasizing behavioural semantics over structural semantics. A key principle guiding the project was compositionality, which had been largely absent in previous research.

The project drew inspiration from OWL-S, which defined a workflow-oriented orchestration language for composing semantic web services, and WSMO, which distinguished orchestration from choreography as an external client perspective. Cashew introduced two formal languages:

  • Cashew, which described choreographies (communication interfaces) and orchestrations (the coordination of multiple service goals).
  • CaSE, which defined asynchronously concurrent processes, one-to-one synchronous communications, and multi-party synchronisations with implicit priority.

The project aimed to address gaps in existing service composition semantics by introducing a compositional approach. Instead of defining a formal behavioural semantics directly for OWL-S, it introduced two intermediate languages. The first allowed greater flexibility in composing workflows, particularly in defining dataflows separately from process execution. The second, CaSE, was a process calculus extending CCS, providing structured operational semantics via labelled transition systems. This enabled orchestration of choreographies as abstract state machines for execution and analysis.

The project’s results contributed to WSMO by defining an ontology for orchestrations and choreographies, which could be visualised in UML Activity Diagrams and translated into abstract state machines (ASMs), the formalism adopted by WSMO.

Project History and Personnel

The Cashew project originated as a Master’s research project within the Darwin module at the University of Sheffield. Two original members, Simon Foster and Andrew Hughes, continued working on related PhD research. Barry Norton moved from the University of Sheffield to the Open University’s Knowledge Media Institute (KMI) as a Research Fellow in Semantic Web Services, continuing collaboration between KMI and Sheffield.

The project produced an orchestration engine written in Haskell, extending Simon Foster’s Haskell Interoperation Framework/Architecture (HAIFA), both of which remained under development. While an Eclipse-based editor for Cashew-S workflows had been considered, it was later discontinued.

Team

Barry Norton
Simon Foster
Carlos Pedrinaci
Andrew Hughes.
Ravish Bhagdev
Xian Liu
Atheesh Sanka

Publications

Norton, B. (2005) ‘Experiences with OWL-S, Directions for Service Composition: The Cashew Position’, OWL: Experiences and Directions Workshop (OWLED 2005), co-located with ISWC.

Norton, B., Foster, S. and Hughes, A. (2005) ‘A Compositional Operational Semantics for OWL-S’, 2nd Workshop on Web Services and Formal Methods (WS-FM 2005).

Foster, S., Hughes, A. and Norton, B. (2005) ‘Composition and Semantic Enhancement of Web Services: The CASheW-S Project’, 1st Young Researchers Workshop on Service-Oriented Computing (YRSOC 2005).

Norton, B. (2005) ‘Cashew: Towards a Reconciliation of ChOrch in IRS, Configurator and WSMO’, DIP Meeting, 10 October.

Norton, B. (2005) ‘A Compositional Operational Semantics for OWL-S’, 2nd Workshop on Web Services and Formal Methods (WS-FM 2005).

Foster, S. (2005) ‘Composition and Semantic Enhancement of Web Services: The CASheW-S Project’, 1st Young Researchers Workshop on Service-Oriented Computing (YRSOC 2005).