DAMLS Semantic Markup for Web Services DAMLS Web

DAML-S: Semantic Markup for Web Services DAML-S Web Services Coalition presented by: Terry R. Payne Carnergie Mellon University http: //www. daml. org/services/

DAML-S Web Services Coalition CMU: Anupriya, Ankolekar, Massimo Paolucci, Terry Payne, Katia Sycara BBN: Mark Burstein Nokia: Ora Lassila Stanford KSL: Sheila Mc. Ilraith, Honglei Zeng SRI: Jerry Hobbs, David Martin, Srini Narayanan [Yale: Drew Mc. Dermott & Manchester: Ian Horrocks] Slides courtesy of Sheila Mc. Ilraith, Stanford KSL

What is DAML-S? DAML-S: A DARPA Agent Markup Language for Services n DAML+OIL Ontology for (Web) services AI-inspired markup language: n n tailored to the representational needs of Services expressive power well-defined semantics ontologies support reuse, mapping, succinct markup, . . . Release of DAML-S version 0. 5 June, 2001 n http: //www. daml. org/services/

Layered Approach to Language Development The first major application of DAML+OIL Layer exists above DAML+OIL Future versions will build upon emerging layers (e. g. DAML-Rules etc) DAML-S (Services) DAML+OIL (Ontology) RDFS (RDF Schema) RDF (Resource Description Framework) XML (Extensible Markup Language)

DAML-S Objectives Provide: n an upper ontology for describing properties & capabilities of agents & (Web) services in an unambiguous, computer interpretable markup language. Desiderata: n n an ontology of Web services ease of expressiveness enables automation of service use by agents enables reasoning about service properties and capabilities

Automation Enabled by DAML -S Web service discovery Find me a shipping service that transports goods to Dubai. Web service invocation Buy me 500 lbs. powdered milk from www. acmemoo. com Web service selection, composition and interoperation Arrange food for 500 people for 2 weeks in Dubai. Web service execution monitoring Has the powdered milk been ordered and paid for yet?

Upper Ontology of Services

DAML-S: Presenting Service Profiles Service Profile n n Presented by a service. Represents “what the service provides” n One can derive: w Service Advertisements w Service Requests

DAML-S Service Profile (Overview) High-level description of a service and its provider n n n description of service (human readable) specification of functionalities service provides functional attributes (requirements and capabilities) Profile used for n n n populating service registries automated service discovery matchmaking

DAML-S Service Profile (Overview) Functionality Description Provenance Description Functional Attributes

DAML-S Service Profile Provenance Description Information and Provenance about the Service n n service. Name & text. Description intended. Purpose & role of 3 rd Party Actors Details about n n n 3 rd Party Actors Requesters Providers

DAML-S Service Profile Functionality Description Specification of what the service provides n High-level functional representation in terms of: w preconditions w access. Conditions w inputs w outputs w conditional. Outputs w effects Summarizes the top-level Composite Process (described by Service Model)

DAML-S Service Profile Functional Attributes Provide supporting information about the service, including: n n geographical scope Pizza Delivery only within the Pittsburgh area quality descriptions and guarantees Stock quotes delivered within 10 secs service types, service categories Commercial / Problem Solving etc service parameters Average Response time is currently. . .

Upper Ontology of Services

DAML-S: Describing Service Models Service Process n Describes how a service works. Facilitates n n (automated) Web service invocation composition interoperation monitoring

DAML-S Service Model (Overview) Service Model may be used to to perform a more in-depth analysis of whether the service meets its needs; 2) to compose service descriptions from multiple services to perform a specific task; 3) during the course of the service enactment, to coordinate the activities of the different participants; 4) to monitor the execution of the service. 1) For non-trivial services, the first two tasks require a model of action and process, the last two involve, in addition, an execution model.

DAML-S Service Model (Overview)

DAML-S Service Model “How does it work? ” Each service is conceived as simple or composite process (event/action) Associated with each service is a set of inputs, outputs, preconditions and effects (function and action metaphor) Composite processes are compositions of simple or other composite processes in terms of constructs such as sequence, if-then-else, fork, . . . Data flow and Control flow should be described for each composite service A black box and glass box view are given of each composite service

Function/Dataflow Metaphor Input: • customer name • origin • destination • weight • pickup date • . . . Output: • confirmation # • . . . Acme Book Truck Shipment truck available + ? valid credit card Y N • failure notification • …

AI-inspired Action/Process Metaphor Output: Input: • customer name • origin • destination • pickup date • . . . Preconditions: • knowledge of the input • . . . Effect: Acme Book Truck Shipment • confirmation # • . . . • goods at location if successful • credit card debited. . . truck available + ? valid credit card Output: Effect: Y N • failure notification • … <no effect>

Composite Process Output & Effects Acme. Truck. Shipping • customer name • location • car type • dates • credit card no. • . . . Input & Preconditions • • • • • www. acmecar. com ? book car service • failure notification • … • confirmation no. • . . . • customer name • flight numbers • dates • credit card no. • • . . . • • • confirmation no. • . . . www. acmeair. com book flight service ? • confirmation no. • dates • room type • credit card no. • . . . www. acmehotel. com book hotel service ? • failure notification • … • failure notification • errror information • … ? • •

Composite Process (cont) Acme. Truck. Shipping Expanded. Acme. Truck. Shipping Confirm Shipping Region Acme Truck Shipping Service expands N truck available + valid credit card Y Get Quote Get Shipping Dates Book Truck Shipment

Composite Process (cont) Acme. Truck. Shipping expand Exp. Acme. Truck. Shipping

Upper Ontology of Services

DAML-S: Supporting a Service Grounding Service Process n Provides a specification of service access information. Specifies: n n communication protocols, transport mechanisms, etc. E. g. , SOAP, HTTP forms, KQML, OAA ACL, Java RMI, RPC, etc. Under Construction …

Review: Upper Ontology of Services

Related Work Related Industrial Initiatives w. UDDI w. WSDL w. XLANG n n web. XML w(dot). NET w. Biz. Talk, e-speak etc These XML-based initiatives are currently complementary to DAML-S intends to build on top of these efforts exploiting increased expressiveness, semantics, inference that enables automation. Related Academics Efforts n n n Process Algebras (e. g. , Pi Calculus) Process Specification Language (Hoare Logic, PSL) Planning Domain Definition Language (PDDL) Business Process Modeling (e. g. , BMPL) Service Description Languages (e. g. , LARKS)