Slide1 IESS1.0,Geneva,Feb2010BSDL,UoW–fundedby

Definition of a Description Language for Business Service Decomposition

Lam-Son Lê, Aditya Ghose, Evan Morrison School of Computer Science and Software Engineering

University of Wollongong (UoW) Australia

Slide2 IESS1.0,Geneva,Feb2010BSDL,UoW–fundedby

Outline

•  Services - An introduction •  Representation Spectrum of Services •  BSDL - Contribution •  Related Work & Future Work

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Context

•  IT & business operated by services – BMS –  ITIL

•  Services at various perspectives: universal, IT-enabling, business

•  Services & Strategy correlation

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Example

Bridge Construction

Cost: 2’000’000 Schedule: 28 months

Penalty: 6 % deduction on cost for every month late

Pre-construction clearance

Cost: 300’000 Schedule: 6 months

Penalty: 10 % deduction on cost for every week

late

Pillars construction

Cost: 350’000 Schedule: 5 months

Penalty: 8 % deduction on cost for every week late

Span construction

Cost: 600’000 Schedule: 4 months

Penalty: 12 % deduction on cost for every week

late

Lighting Facility

Cost: 150’000 Schedule: 3 months

Penalty: 9% deduction on cost for every week late

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To describe business services

1.  Provider and Requester (Customer) 2.  Capabilities 3.  Non-functional Properties 4.  Decomposition 5.  Distribution of (2) and (3)

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Representation Continuum

Net work of web services and their interaction Internet of generic services Goal-oriented

requirements

Business services and service decomposition Business processes

Business strategy

Execution of web services

<message name="GetLastTr"> </message> <portType ame="StockQuotePortType">

<wsag:ServiceDescriptionTerm wsag:Name=„EcoInf" wsag:ServiceName=„Eco Calc"> <usdl:ServiceDescription> <usdl:ServiceName>Eco Calculator</usdl:ServiceName>

SML BSDL USDL BPEL4WS GRL BPMN WSDL

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Existing Work on Business Services

•  Description of Service Capabilities and Properties – (DSCP) http://service-description.com/ – Capabilities – Non-functional Properties – Language (meta-)presented in ORM

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BSDL

•  Is based on DSCP •  More concepts added to address

– Service decomposition – Additional non-functional properties

•  Meta-modelled in UML – good input for tool implementation in Eclipse

•  Formalized in Alloy

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BSDL: Meta-model

Rule Description

Acyclic There must be no cycle along the decomposition

hierarchy of business services.

Mutual For each business service, all properties and

capabilities declared in it must take it as their sole

service.

Uniqueness The set of parameters of two different signatures must

be different.

Same service

An obligation and corresponding penalties

must be of the same business service.

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BS

DL

Met

a-m

odel

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Alloy as Formalization Language

•  Alloy language –  Is a declarative modeling language based on

1st order logic and set theory – Has OO syntax

•  Benefits of using Alloy – Building blocks & well-formedness rules

formalized together – Alloy Analyzer tool enables:

•  consistency checking •  visualization an instance model

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Formalized in Alloy

Decomposition

1 decomposedService

sig Decomposition { decomposedService: one BusinessService, constituentServices: some BusinessService }

fact acyclic { all e: seamHierarchicalElement | e not in (e.^components + e.^parent) }

sig Subcontracting extends Decomposition { }

Subcontracting

Business Service constituentServices 1..*

Slide13 IESS1.0,Geneva,Feb2010BSDL,UoW–fundedby

Well-formedness rules in Alloy

sig Decomposition { decomposedService: one BusinessService, constituentServices: some BusinessService }

fact acyclic { all bs: BusinessService | bs not in bs.^(~decomposedService.constituentServices) and

bs not in bs.^(~constituentServices.decomposedService) }

sig Subcontracting extends Decomposition { }

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Alloy code

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Using Alloy Analyzer

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Implementation

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Related Work

•  SLA@SOI •  WSDL •  DSCP •  USDL •  SML

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Conclusion

•  Services from a business perspective •  DSCP defines business services, service

capability and non-functional properties •  More concepts needed •  BSDL addresses

– service decomposition – schedule, penalty…

•  BSDL defined using UML and Alloy

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Future work

•  Improvement of BSDL – Decomposition of Capabilities – Distribution of Non-Functional Properties

•  Strategic alignment of business services •  Evaluation

– Case-studies with CRC industrial partners – Toolkit

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Thank you!