© Copyright Mick Kerrigan and Barry Norton Semantic Execution Environments Service Engineering and Execution

Plan for the Day Review and reinforcement of WSMO model for services and Semantic SOA Reference Ontology Semantic Execution Environment (SEE) Reference Architecture Semantic Web Service Engineering Scenarios Web Service Modelling Toolkit (WSMT) Hands-on with SEE and WSMT The Future for Service Engineering 2

Semantic Web Service Engineering Scenarios Semantic Web Service Applications can have very different architectures based on the problems they aim to solve Different groups of SEE broker services can be brought together The following scenarios provide an overview of different application scenarios For each the set of SWS artifacts needed to realize the scenario are described Scenarios can be combined to solve more complex problems 3

Scenario 1: Using Semantic Web Services for Service Advertisement A key problem with SOA is that of service management –What services exist? –What functionality do they have? Semantic Web Services can be used to enable the creation of an intelligent service repository 4 Goal Description Goal Description Intelligent Service Repository Discovery Service Discovery Service Storage Web Service Description Web Service Description Web Service Description Web Service Description Web Service Description Web Service Description Web Service Description Web Service Description Publish Query Provider Requester Ranking Service Ranking Service

Scenario 1a: Capability-Based Service Advertisement Capability in Goal is compared with Capability in each Service Current approaches to Capability Based Discovery include –Lightweight Only Postconditions Description Logic or Logic Programming based –Heavyweight Assumptions, Preconditions, and Postconditions Logic Programming Based 5

Scenario 1a: Capability-Based Service Advertisement 6 G WS Exact Match WS G Plugin Match G WS Subsumption Match G WS Intersection Match GWS No Match

Scenario 1a: Capability-Based Service Advertisement (Provider Perspective) 7 Engineer Mediator Descriptions Engineer Ontologies Engineer Service Descriptions Engineer Goal Descriptions WSMO Ontologies Engineer Capability Engineer Capability Engineer NFPs WSMO Web Service

Scenario 1a: Capability-Based Service Advertisement (Requester Perspective) 8 Engineer Mediator Descriptions Engineer Ontologies Engineer Service Descriptions Engineer Goal Descriptions WSMO Ontologies Engineer Capability Engineer Capability Engineer NFPrefs WSMO Goal

Scenario 1b: Mediator-Based Service Advertisement Provider describes a new service and defines a wgMediator linking to goals that the service fulfils Provider may classify the new service in a hierarchy using a wwMediator Requester identifies a goal to be instantiated and instantiates it Requester may tie the new goal to the goal it instantiates using a ggMediator A match is identified if a wgMediator exists between the goal instantiated by the requester and a service 9

Goal Template Goal Template Goal Template Goal Template Goal Template Goal Template Goal Template Goal Template Goal Template Goal Template Web Service Description Web Service Description Web Service Description Web Service Description Web Service Description Web Service Description Web Service Description Web Service Description Scenario 1b: Mediator-Based Service Advertisement 10 Web Service Description Web Service Description Goal Instance Goal Instance

Scenario 1b: Mediator-Based Service Advertisement (Provider Perspective) 11 Engineer Mediator Descriptions Engineer Ontologies Engineer Service Descriptions Engineer Goal Descriptions Engineer NFPS WSMO Web Service Engineer WWMediator Engineer WWMediator WSMO WW Mediator Existing WSMO Web Services Existing WSMO Web Services Engineer WGMediator Engineer WGMediator WSMO WG Mediator Existing WSMO Goals Existing WSMO Goals WSMO Ontologies

Scenario 1b: Mediator-Based Service Advertisement (Requester Perspective) 12 Engineer Mediator Descriptions Engineer Ontologies Engineer Service Descriptions Engineer Goal Descriptions Existing WSMO Goals Existing WSMO Goals Engineer NFPrefs WSMO Ontologies WSMO Goal Engineer GGMediator Engineer GGMediator WSMO GG Mediator

Scenario 2: Using Semantic Web Services for Service Invocation In a counter scenario the critical problem may be maintaining the integration between changing services –How to automatically maintain the integration between services as they change Semantic Web Services can enable the automatic execution of services through the semantic description of their external visible behavior 13 Goal Description Goal Description Web Service Description Web Service Description Publish Invoke Provider Requester Web Service Identifier Web Service Identifier Automatic Service Invoker Process Mediation Process Mediation Storage Process Execution Process Execution

Scenario 2: Using Semantic Web Services for Service Invocation 14 Web Service Description Service Web Service Descriptio n Web Service Descriptio n Web Service Descriptio n Web Service Descriptio n Ontology Instances Web Service Descriptio n Web Service Descriptio n Web Service Descriptio n Web Service Descriptio n XML Data XML Data Goal Description Service Web Service Descriptio n Web Service Descriptio n Web Service Descriptio n Web Service Descriptio n XML Data XML Data

Scenario 2: Using Semantic Web Services for Service Invocation (Provider Perspective) 15 Engineer Mediator Descriptions Engineer Ontologies Engineer Service Descriptions Engineer Goal Descriptions WSMO Ontologies Lifting & Lowering Mappings Engineer Grounding Engineer Choreograph y WSMO Web Service

Scenario 2: Using Semantic Web Services for Service Invocation (Requester Perspective) 16 Engineer Mediator Descriptions Engineer Ontologies Engineer Service Descriptions Engineer Goal Descriptions WSMO Ontologies Lifting & Lowering Mappings Engineer Grounding Engineer Choreograph y WSMO Goal

Scenario 3: Using Semantic Web Services for Service Composition In many cases no single service will be enough to fulfill the end users Goal and a composition of a number of services must be built There are two key scenarios where service composition can occur: –Some actor identifies a set of services that complement each other and decides to build a composition at design-time –In a Semantic Execution Environment no service exists that can fulfill the end users requirements so a composition must be built at run-time In the first scenario the composition is provider driven, while in the second scenario the composition is requester driven 17

Scenario 3a: Design-time Service Composition Provider driven service composition Virtual Provider identifies a set of Semantic Web Services that can be composed to offer a useful coarser grained service New composition is created by describing –The external visible behavior of the composition in terms of choreography –The way in which individual services (or goals) are combined in terms of orchestration Service requester can discovery and invoke this new composed service just like any existing service 18

Scenario 3a: Design-time Service Composition (Provider Perspective) 19 Engineer Mediator Descriptions Engineer Ontologies Engineer Service Descriptions Engineer Goal Descriptions Existing WSMO Web Services Existing WSMO Web Services WSMO Ontologies Engineer Choreograph y WSMO Web Service Engineer Orchestration

Scenario 3b: Run-time Service Composition Requester driven service composition Discovery has not found a single service that offers the required functionality to meet a particular need Requester drives an automated process of service composition by providing –A description of the desired functionality (mandatory) –A description of the desired non functionality aspects of the service (optional) –A description of the external choreography of the new composition (optional) –A full or partial description of the way in which services should interact (optional) An entire or partial plan for the orchestration A description of particular services that must be included in the orchestration 20

Scenario 3b: Run-time Service Composition (Requester Perspective) 21 Engineer Mediator Descriptions Engineer Ontologies Engineer Service Descriptions Engineer Goal Descriptions WSMO Ontologies Engineer Capability Engineer Capability Engineer NFPrefs WSMO Goal Engineer Choreograph y Engineer Orchestration Lifting & Lowering Mappings Engineer Grounding

Scenario 4: Engineering Ontologies in a Semantic Web Service Context Scenarios 1 to 4 show the need for ontologies that can be used to describe capabilities, non functional properties and preferences, choreographies, and orchestrations Many ontology engineering methodologies exist that can be used to build these ontologies Such methodologies should be used in a Semantic Web Service Engineering Context by Semantic Web Service engineers However, there are a number of cases that should be taken into consideration when building ontologies for describing Web Services and Goals 22

Scenario 4a: Engineering Ontologies from XML Schema 23 Engineer Mediator Descriptions Engineer Ontologies Engineer Service Descriptions Engineer Goal Descriptions WSMO Ontologies XML Schema Engineer Ontology Engineer Ontology

Scenario 4b: Reusing Existing Ontologies 24 Engineer Mediator Descriptions Engineer Ontologies Engineer Service Descriptions Engineer Goal Descriptions WSMO Ontologies Existing Ontologies Existing Ontologies Choose Ontology

Scenario 4c: Reengineering Existing Ontologies 25 Engineer Mediator Descriptions Engineer Ontologies Engineer Service Descriptions Engineer Goal Descriptions WSMO Ontologies Existing Ontologies Existing Ontologies XML Schema Reengineer Ontology Reengineer Ontology

To ensure interoperability between Web services and Goals using different ontologies mediators are required –Between local ontologies defined by providers and requesters –Between local ontologies and commonly used ontologies –Between commonly used ontologies Ontology Scenario 5: Enabling Interoperation Between Ontologies 26 Ontology Instance Transformer Data Mediation Service Data Mediation Service Mapping Repository Mapping Repository Ontology Repository Web Service Descriptio n Web Service Descriptio n Web Service Descriptio n Web Service Descriptio n Ontology Instances Web Service Descriptio n Web Service Descriptio n Web Service Descriptio n Web Service Descriptio n Ontology Instances Ontology Ontology to Ontology Mappings Runtime Design time

Scenario 5: Enabling Interoperation Between Ontologies 27 Engineer Mediator Descriptions Engineer Ontologies Engineer Service Descriptions Engineer Goal Descriptions Existing Ontologies Existing Ontologies WSMO Ontologies Engineer OOMediator Engineer OOMediator WSMO OO Mediator Ontology to Ontology Mappings Engineer OO Mappings

Overview of Engineering Activities 28 Engineer Mediator Descriptions Engineer Ontologies Engineer Service Descriptions Engineer Goal Descriptions WSMO Ontologies Engineer Capability Engineer Capability Engineer NFPs Engineer Capability Engineer Capability Engineer NFPrefs WSMO Goal WSMO Web Service Engineer WWMediator Engineer WWMediator WSMO WW Mediator Existing WSMO Web Services Existing WSMO Web Services Engineer WGMediator Engineer WGMediator WSMO WG Mediator Existing WSMO Goals Existing WSMO Goals Engineer GGMediator Engineer GGMediator WSMO GG Mediator Lifting & Lowering Mappings Engineer Grounding Engineer Choreograph y Engineer Orchestration Engineer Choreograph y Engineer Orchestration XML Schema Engineer Ontology Engineer Ontology Existing Ontologies Existing Ontologies Choose Ontology Reengineer Ontology Reengineer Ontology Engineer OOMediator Engineer OOMediator WSMO OO Mediator Ontology to Ontology Mappings Engineer OO Mappings

Plan for the Day Review and reinforcement of WSMO model for services and Semantic SOA Reference Ontology Semantic Execution Environment (SEE) Reference Architecture Semantic Web Service Engineering Scenarios Web Service Modelling Toolkit (WSMT) Hands-on with SEE and WSMT The Future for Service Engineering 29

Web Service Modeling Toolkit (WSMT) 30

The Web Service Modeling Toolkit (WSMT) The WSMT is an Integrated Development Environment (IDE) for the development of Semantic Web Services Aims to support the engineer through the Software Development Cycle (SDC) of Semantic Web Services –Improve Engineer Productivity –Aid in adoption of WSMO, WSML, SEE –High quality tools –Eclipse based 31

WSMT Functionality Development of WSMO Semantic Descriptions through WSML –Ontologies –Goals –Web Services –Mediators Interfacing with Semantic Execution Environments –WSMX –IRSIII Creation of Mediation Mappings between Ontologies –Abstract Mapping Language (AML) 32

WSML Perspective Semantic Execution Environments need Ontologies, Goals, Web Services, and Mediators in order to function Provide support to the engineer in creating these descriptions Provide mechanisms for browsing semantic descriptions to aid in developer understanding Abstract the developer from the underlying syntax Assist in the validation and testing of semantic descriptions 33

WSML Text Editor Abstracting from syntax is good but… Existing developers familiar with the syntax Certain tasks are just easier with a textual representation WSML Human Readable Syntax is designed to be light Must support the more experienced developer 34

WSML Text Editor 35

WSML Form Based Editor Abstracts developers from the WSML syntax allowing them to focus on the modeling task at hand –Improved Developer focus –Reduced Errors in semantic descriptions –Less keystrokes improves speed of creation Descriptions are broken up into tabs to keep the forms small Forms consist of Text fields, combo boxes and tables 36

WSML Form Based Editor 37

WSML Visualizer In Textual, Form or Tree based representations it is hard to see the full relationship between entities Graph based representations give a better “Feel” for the complexities of a semantic description However normally visualizers are bolted on top of existing tools The WSML Visualizer provides editing and browsing support in one tool Immediate feedback to the developer as semantic descriptions are being created 38

WSML Visualizer 39

Creating Entities 40

WSML Navigator Used to Navigate the workspace Default editor can be opened with a double click Other editors can be be opened by “Right Click  Open With” Elements can be expanded to see the content with them Informational annotations show files with errors and warnings 41

WSML Navigator 42

WSML Wizards 43

Interoperability with other languages WSML ontologies can be transformed to OWL and RDFS to enable Web compliance WSMT can perform this transformation within the WSML Navigator Existing RDFS or OWL files can be transformed into a WSML representation WSML can be transformed in the RDFS or OWL depending on the WSML variant 44

Convert To 45

Finding WSML Entities With large workspace it can be hard or tedious to find the element you want to open WSML Cache View allows the navigation of all Ontologies, Web Services, Mediators and Goals. Double click to open the file they are contained in Find Entity dialog can be launched with Ctrl-Shift-T and allows entities to be searched for by name. Selection will open the file they are contained in and select them 46

WSML Cache View 47

Open Entity 48

Outline View The outline view gives a structured view of a WSML file Can be used in conjunction with any of the editors in the WSMT Provides a browsing mechanism for any WSML description Selecting an entity in the view will select the relevant entity in the editor View can be filtered to reduce the content that is displayed 49

WSML Outline View 50

Validation WSMO4J parser used to validate syntax WSMO4J validator used to validate semantics –Ensures features within the semantic description match that of the specified WSML Variant (Errors) –Checks for unrecommended usage of WSML Features (Warnings) Discovery engine used to validate Web Services and Goals –Compliance to structure of discovery approaches All files automatically checked as they are changed Immediate feedback to the user in each editor 51

Problem View 52

Testing Testing software usually involves deploying it and ensuring that it functions as expected Involves a costly Deploy-Test-Redeploy cycle Support within an IDE for testing software in its natural habitat can vastly reduce this iterative process –Reduces the cost of development –Improves developer productivity –Reduced developers involvement in tedious tasks Correctness of a semantic description is more than just having a valid description 53

Testing Ontologies Ontologies underlie every other semantic description in WSML The developer needs to be sure that each ontology behaves as expected when used in a reasoner –Is the ontology consistent? –Does is answer queries in the manner expected? Access to reasoners for each of the WSML Variants is thus required within the WSMT Allow users to perform reasoning operations over the ontology currently being edited 54

WSML Reasoner View 55

Executing a Predefined Query Template 56

Defining a Predefined Query Template 57

Defining a Predefined Query Template 58

Testing Web Services and Goals A Semantic Web Service that does not match the Goals it is expected to match could result in the loss of a lot of money Developers need to ensure that the Web Service descriptions that create match Goals as expected Tool support reduces the number of interactions with a testing SEE Quite likely that provider will issue sample Goals with their Web Service descriptions. Ensuring your Web Service descriptions are found by your competitors sample Goals could provide a competitive advantage. 59

WSML Discovery View 60

Configuring the WSMT 61

Interfacing with a SEE In order for a SEE to correctly function the necessary Ontologies, Goals, Web Services and Mediators need to be available to it Manually deploying descriptions to a SEE or manually retrieving them in order perform maintenance is a tiresome and lengthy process Automated tools for interfacing with the Web Services exposed by a SEE enable these actions to be reduced to one or two clicks of a mouse. The SEE perspective contains all the functionality necessary to deliver this tool support to the developer 62

Interacting with SEE’s 63

Interacting with SEE’s 64

Interacting with SEE’s 65

Ontology Mediation Service Consumers and Providers may not agree on terminology Instance transformation can transform instances from the consumers ontologies to instances of the providers ontologies Automatic approaches use algorithms to detect alignment between the source and target ontologies –Low precision –No developer involvement required Manual approaches rely on the developer creating the alignment by hand –Can get 100% accuracy –A lot of work needed to create all the mappings 66

Ontology Mediation (WSMX/WSMT) 67

View based Editor An editor with for creating mappings using drag and drop Different views all for different types of mappings to be created: –Part of view: C2C, A2A, C2A, A2C –Instance of view: conditional mappings –RelatedBy view: R2R Guides the developer through the process of creating these mappings using embedded suggestion algorithms 68

Ontology to Ontology Mapping 69

Mapping Views As ontologies become bigger mappings can be harder to see View based editor also obscures the type of the mapping Provide the developer with a mechanism for quickly seeing mappings by type Provide a mechanism for deleting one or more mappings 70Asian Semantic Web School, 3/12/ :30-16:00

Browsing Ontology to Ontology Mappings 71

Testing Developers need to be confident in the mappings they create Testing involves ensuring that a given set of source instances translate into the expected set of target instances Very time consuming task involving a lot of tedious work Automation of comparison enables engineer to quickly perform tests –Ensure mappings still valid as ontologies evolve –Ensure mappings behave as expected on different reasoners 72Asian Semantic Web School, 3/12/ :30-16:00

Unit Testing Ontology to Ontology Mappings 73

Browsing the results of a MUnit Test 74

Configuring the WSMT 75

Plan for the Day Review and reinforcement of WSMO model for services and Semantic SOA Reference Ontology Semantic Execution Environment (SEE) Reference Architecture Semantic Web Service Engineering Scenarios Web Service Modelling Toolkit (WSMT) Hands-on with SEE and WSMT The Future for Service Engineering 76

Plan for the Day Review and reinforcement of WSMO model for services and Semantic SOA Reference Ontology Semantic Execution Environment (SEE) Reference Architecture Semantic Web Service Engineering Scenarios Web Service Modelling Toolkit (WSMT) Hands-on with SEE and WSMT The Future for Service Engineering 77

Web 3.0 Returning to the First Day 78 UGC Semantics Dynamism Web Services Web Semantic Web Services Semantic Web Web 2.0 Web of Applications

Next Big Challenge 79 Web 3.0 UGC Semantics Dynamism Web Services Web Semantic Web Services Semantic Web Web 2.0 Service Web Web of Applications