OWL-S

Web Services: OWL-S2 BPEL and WSDL : Messages

Web Services: OWL-S3 Messaging and Message-Oriented Modeling Fundamental in composition: how and when the processes communicate Synchronous, asynchronous Conversations However, business processes center around “activities” and compositions of tasks: Control flow Data flow Messaging provides a realization of control/data flow Unclear how activities and messaging would mix

Web Services: OWL-S4 Activity Based Models OWL-S (DAML-S) Finite state machines and statecharts Petri nets Process Specification Language (PSL) …

Web Services: OWL-S5 OWL-S/DAML-S An upper ontology for describing the properties & capabilities of agents & (Web) services in an unambiguous, computer interpretable markup language Built as an additional layer above DAML+OIL/OWL Designed to the following automated tasks…

Web Services: OWL-S6 Automation Enabled by OWL-S Web Service Discovery & Selection Find an airline that can fly me to New York, NY Web Service Invocation Book flight tickets from USAirways to arrive May 18 Web Service Composition & Interoperation Arrange taxis, flights and hotel for travel from Santa Barbara to Boston, MA, via New York, NY Web Service Execution Monitoring Has the taxi to Newark Airport been reserved yet?

Web Services: OWL-S7 Resources are related to each other by properties to form subject/predicate/object statements (triples) The triples can be used to construct a graph: Statements themselves can be resources of other statements (i.e. reified statements) “W3C Home Page” “WWW Consortium” subject predicate object predicate RDF – Resource Description Framework

Web Services: OWL-S8 RDF Schema RDF Schema defines new RDF vocabulary & hence definition of ontologies… rdfs:Class resources denoting a set of resources, by means of the property rdfs:type rdfs:subClassOf Used to define class hierarchies. rdfs:domain & rdfs:range Define restrictions on the resources that have a given property (domain) and the set of valid values for that property (range)

Web Services: OWL-S9  input types  output types  preconditions  postconditions  communication protocol (RPC, HTTP, …)  port number  marshalling/serialization  process flow  composition hierarchy  process definitions

Web Services: OWL-S10 Resource Service Service Profile Service Model Service Grounding  communication protocol (RPC, HTTP, …)  port number  marshalling/serialization  input types  output types  preconditions  effects  process flow  composition hierarchy  process definitions provides presents (what it does) describedby (how it works) supports (how to access) OWL-S Upper Ontology

Web Services: OWL-S11 OWL-S Service Models Resource Service Service Profile Service Model Service Grounding provides presents (what it does) describedby (how it works) supports (how to access)

Web Services: OWL-S12 Service Profile Presented by a service Represents “what the service provides” One can derive:  Service Advertisements  Service Requests Presenting Service Profiles

Web Services: OWL-S13 Non Functional Properties Functionality Description OWL-S Service Profile

Web Services: OWL-S14 Functionality Description Summarizes the abstract capability of a service Functional specification of what the service provides in terms of parameters, subclassed as: preconditions inputs outputs effects

Web Services: OWL-S15 Functionality Description: Parameters Preconditions Set of conditions that should hold prior to service invocation Inputs Set of necessary inputs that the requester should provide to invoke the service Outputs Results that the requester should expect after interaction with the service provider is completed Effects Set of statements that should hold true if the service is invoked successfully Often refer to real-world effects  Package being delivered, or Credit card being debited

Web Services: OWL-S16 Non Functional Properties Provides supporting information about the service These include serviceName textDescription has_process qualityRating serviceParameter serviceCategory contactInformation

Web Services: OWL-S17 Profile Hierarchy Sub-classing the Profile model facilitates the creation and specialisation of service categories Each subclass can: Introduce new properties Place restrictions on existing properties Sub-classing can also be used to specialise requests for service An example Profile Hierarchy is provided, but others could just as easily be defined

Web Services: OWL-S18 Profile Hierarchy – Sample Ontology

Web Services: OWL-S19 OWL-S Service Models Resource Service Service Profile Service Model Service Grounding provides presents (what it does) describedby (how it works) supports (how to access)

Web Services: OWL-S20 Service Process Describes how a service works Facilitates (automated) Web service invocation composition interoperation monitoring Describing Service Models

Web Services: OWL-S21 The Process Ontology The basic class of the Process Ontology is the Process. Its sublcasses describe each process by: any number of (possibly, conditional) inputs; any number of (possibly, conditional) outputs; any number of preconditions, which must hold in order for the process to be invoked; any number of (possibly, conditional) side effects; any number of participants (subprocess)

Web Services: OWL-S22 Types of the Process in OWL-S Atomic processes: directly invokable (by an agent), have no subprocesses, executed in a single step Composite processes: consist of other (non-composite or composite) processes They have a composedOf property, by which the control structure of the process is indicated, using a ControlConstruct subclasses (see table …) Simple processes: abstract concepts, used to provide a view of some atomic process, or a simplified representation of some composite process (i.e., the “black box” view of a collapsed composite process)

Web Services: OWL-S23 OWL-S Service Model (Overview)

Web Services: OWL-S24 Construct Description Sequence Execute a list of processes in a sequential order Concurrent Execute elements of a bag of processes concurrently Split Invoke elements of a bag of processes Split+Join Invoke elements of a bag of processes and synchronize Unordered Execute all processes in a bag in any order Choice Choose between alternatives and execute one If-then-else If specified condition hold, execute “Then”, else execute “Else”. Repeat-Until Iterate execution of a bag of processes until a condition holds Repeat-While Iterate execution of a bag of processes while a condition holds Control Constructs of Processes

Web Services: OWL-S25 <rdfs:subClassOf rdf:resource= “ /> GetDesired Flight Details Airport Flight Date AtomicProcess departureAirport_In outboundDate_In Atomic Process Example

Web Services: OWL-S26 <rdfs:subPropertyOf rdf:resource= "http: // /> <rdfs:range rdf:resource=" DAML-S/concepts.daml#Airport" /> <rdfs:range rdf:resource=" DAML-S/concepts.daml#FlightDate" /> Atomic Process Example

Web Services: OWL-S27 Composite Process Confirm Reservation BookFlight Get Contact Details Sequence Get Flight Details Reserve Flight Sequence Composite Process Example

Web Services: OWL-S28 OWL-S Service Models Resource Service Service Profile Service Model Service Grounding provides presents (what it does) describedby (how it works) supports (how to access)

Web Services: OWL-S29 Service Grounding Provides a specification of service access information Service Model + Grounding give everything needed for using the service Builds upon WSDL to define message structure and physical binding layer Specifies: communication protocols, transport mechanisms, agent communication languages, etc. Supporting a Service Grounding

Web Services: OWL-S30 Resources/Concepts WSDL OWL-S Process Model Atomic Process Operation Message Inputs / Outputs Binding to SOAP, HTTP, etc. OWL-S / WSDL Binding

Web Services: OWL-S31 OWL-S / WSDL Mapping