Process Views with Flows for Heterogeneous and Complex System

Integration: A Service Requirement Approach

Dickson K. W. CHIUSenior Member, IEEE

kwchiu@acm.org, dicksonchiu@ieee.org

Zhe SHAN, Qing LI City University of Hong Kong

zenga@cs.cityu.edu.hkitqli@cityu.edu.hk

Patrick C. K. HUNGFaculty of Business and Information Technology,

University of Ontario Institute of Technology Patrick.Hung@uoit.ca

S.C. Cheung

Dept. of Computer Science Hong Kong University of Science & Technology

scc@cs.ust.hk

Process Views and

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Introduction B2B Interaction

consists of interoperation and integration with both internal and external enterprise applications

Process View (Workflow views) a structurally correct subset of a workflow interactions inter-operate in a gray box mode providing external access to business processes

Flow a directed relationship that transmits events from a

source activity to a sink activity. partition activity relationships into control-flows, data-

flows, semantic-flows, exception-flows, and security-flows workflow specification is a set of activities connected by

these flows

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Motivation and Objectives

Systematic design of interactions Encapsulated in process views But workflows are too complex for large-scale IS Proposal: consider component flows Different flows: separation of concerns

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Project Background Process View (implementation and requirement engineering

immature) D.K.W. Chiu et al. Information Technology and Management,

5(3/4):221-250, 2004. D.K.W. Chiu et al. Distributed and Parallel Databases 12(2-3):193-

216, 2002. Process View Implementations with Web Services

Z. Shan, D.K.W. Chiu and Q. Li. Systematic Interaction Management in a Workflow View Based Business-to-business Process Engine, HICSS38, Jan 2005 (best paper nomination).

Flows P.C.K. Hung and Dickson K.W. Chiu. Developing Workflow-based

Information Integration (WII) with Exception Support in a Web Services Environment, HICSS37

Preliminary version D.K.W. Chiu, Z. Shan, P.C.K. Hung and Q. Li. Designing Workflow

Views with Flows for Large-scale Business-to-Business Information Systems, 5th VLDB Workshop on Technologies for E-Services (TES-04), Toronto, Canada, Aug 2004.

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Conceptual Model of Process View and Flows

Data Flow Data Flow View

Control Flow Control Flow View

Semantic Flow Semantic Flow View

Exception Flow Exception Flow View

Security Flow Security Flow View

Flow ViewMessage

Activity

Flow

Process

Process View

Organization

offer to+service

+requestor

+destination

+incoming+outgoing

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Control Flows

Control flows specify the execution order of activities which are allowed in the processes

Process logic in a cross-organizational process

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Data Flows

define the flow of specific data or dataset required by a process.

may often be almost the same as the control flows in processes that involve only simple data exchange

In HCSI many data flow in parallel control flows are often inadequate, inflexible, or

unclear for expressing data exchange sequence.

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Security Flows

define the flow of security control information, e.g., authentication

creation, exchange, and revocation of security tokens to implement security policies represent a collection of claims (i.e., user ID information) like name, identity, privilege, and capability authentication and authorization

security policy set of laws, rules, and practices regulate how a flow prevents information and resources

from being misused support the principle of single-sign-on

delegation or propagation should be well designed and described

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Semantic Flows

Define the semantic relationship among the information used in the process execution

Abstract the main concepts and describe their dependence in a more precise way.

Such data schema can be represented in OWL as ontology.

Assume partner organizations have an agreed semantics of the information exchanged

stored in a common UDDI directory heterogeneous ontology and ontology integration

problems as future work

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Exception flow

convey the occurrence of such exceptions from the service provider to the requestor

trigger the corresponding exception handler processes pre-defined at the requestor side

unexpected exceptions require human attention and handling send alerts to the appropriate personnel

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Overview of Flows

exception-flow

data-flow-1

data-flow-2

data-flow-N

IDrecord CrimeRecord BorderRecord

data-flow-(N -1)

data-flow-(N -2)

data-flow-(N -3)

CrimeRecord BorderRecord BankRecord

join join-attributes

security-flow

SingleSign On

SingleSign On

SingleSign On

SingleSign On

Generatesecurity-token security-token

revoke security-token

security-token

security-token

SessionStart

SessionEnd

revoke security-token

revoke security-token

Start EndCrimeCheck

BankCheck

IDCheck

initialized keys-transferred

completed

completed

keys-transferred

join join

BorderCheck

completedkeys-transferred

control-flow

semantic-flow

Identity

Legal

Custom

Banking

reference

trigger

link

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e-Government Integration Case Study

IDrecord (id-no, tax-file-no, name, sex, date-of-birth, area-code, phone-no, address, postal-code) are hold by the Immigration Department (in the case for Hong Kong).

BorderRecord (id-no, entry-or-exit, place, vehicle, day-of-event) are hold by the Immigration Department.

CrimeRecord (id-no, crime-description, sentence, day-of-event) are hold by the Police.

BankRecord (tax-file-no, bank-no, account-no, transaction, amount, balance, day-of-event) are hold by individual banks.

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Methodology Overview

Basic Service Provision Elicit the flows required for service provision Analyze flows and formulate view for

different types of users HCSI by composing basic services

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Eliciting Flows for Service Provision Determine the main processes (e.g., ID service process and border

record service process) that are offered to partners as services. For each of the main service process, determine the sub-services,

which includes different service options (e.g., single basic ID information, single extend ID information, and batch ID information) and supporting services (e.g., approvals).

Data services provide information and deal with data flow; control services provide procedure automation and deal with control flow; security services deal with security check; exceptions services deal with exception situations.

Usually, data or control services are the main ones to be considered first.

For each service, determine the expected requestors and under which pre-conditions they are allowed to access. These are the incoming flows.

If any of the pre-conditions is related to security, formulate security services that deal with security flow for the checking. A successful security check will become the required pre-condition.

Relate the pre-conditions with any other service constraints, such as limitations of the request parameters.

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Eliciting Flows for Service Provision (cont)

If any security check is related to pre-approval procedures, formulate control supporting services that deals with the control flow of the approval activity. A successful approval activity will initiate a security flow (via an internal token creation service) to grant a security token to the requestor.

For each service, determine the possible outcomes. For each of the outcome, specify the post-conditions and whether

any messages should be sent back to the requestor, any other parties, and/or any internal services. These are the outgoing flows.

If the outcome message is targeted to any internal services, make sure that such service exist, the message is appropriate, and the post-condition of the former service matches with the pre-condition of the latter service.

For each of the services, determine any possible abnormal outcome.

For each abnormal outcome, forward the exception to an exception services (such as an exception manager) that can initiate exception flow towards one or more internal or external targets.

Consider also the provision of exception handler services for handling internal and/or external exception flows.

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Flow Analysis and View Formulation

check for missing ones organize them into process views similar to data flow analysis trace messages and transformations

Identification of Incoming Messages Identification of Outgoing Messages Identification of Immediate Responses of Incoming

Messages Identification of Data and Flow Relevancy Identification of Independent Incoming or Outgoing

Message Pairs View Tabulation

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Views of the ID Service Process to other Departments

Department View Composed of the Flows (numbered in Table I)

Police i1->o1, i1->(o2->)o18, i1->o3, i5->o11, i5->(o12->i13->)o22, i8-> o16,i8-> (o17->i15)->o24, i15->o25

Customs i3->o7, i3->(o8->i10->)o19, i6-> o13,i6->(o14->i14->)o23, i8->o16,i8->(o17->i15->)o24, i15->o25

Other Govt. Users

i4->o9, i4->(o10->)o19, i8->o16,i8->(o17->i15->)o24, i15->o25

Central IT Security Center

i8->(o17->i15->)o25,i7->(o15->i17->)o25,i19->o25,

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HCSI by Service Composition 1. Determine the set of data items D required for the integration.2. Based on the services registered in the common UDDI directory,

determine the service and organization from which those data items can be obtained from. That is, for each item d D, find service s such that OutMsg(s, m) Depend(d, m). Let S denote the set of required services thus found.

3. For each s S, consider InMsg(s, n), the request n required by service s. For each d’ in Depend(d’, n), if d’ D, add d’ into D. Re-iterate from step 1 until no more items can be added to D, i.e., all the transitively dependent data requirements D as well as the set of services S providing them are found.

4. For each s S, consider the pre-condition requirements of the flows. Determine the extra security flow (such as approved security token) and control flow (such as approval applications) required. Re-iterate from Step 1 if extra data items are required or from Step 4 if only extra control and security services are required.

5. Determine any relevant exception flows that could occur and design handler activities / services if necessary.

6. Implement the internal process for the integration of the control, data, security, (semantic,) and exception flows.

7. Now, the new service process is ready. Design process views of this new service process for other organizations, according to the methodology discussed in the previous sub-sections.

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Mapping between the Conceptual Layers and Technologies

Workflow Layer

Privacy Layer

Security Layer

Coordination

Access Control

Conceptual Model Logical Model

Message Layer Orchestration

BPEL4WS

Enterprise PrivacyAuthorization

Language (EPAL)

WS-Security

support

Language Model

SOAPsupport

support

support

map

map

map

map

Semantic Layer OntologyOntology Web

Language (OWL)

supportmap

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System Architecture

Flow & View Definitions

Process View Instances

Flow & View Editor

Public UDDI Directory

View Runtime Manager

Web Services Interface

Flow Manager

Interaction Monitor

Process View Engine

Process Definitions

ProcessExecutor

ExceptionManager

Process Instances

ProcessEditor

System Integration Flows

Interaction Manager

Interaction Log

Internal Process Engine

Partner Organizations …

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Graphical XML Representation of a Process View

Commen t edited with XMLSPY v 2004 rel . 4 U (http :/ /ww w.xmlsp y.com ) by zhe shanp r o c e s s

n a m e IntelligenceBureau&CityBan kt a r g e t N a m e s p .. . http://ww w .dickso n-compute r.com /servic e/WorkflowVie wx m l n s http://schema s . xmlsoap .org/ws/2003/0 3/busines s -proces s/x m l n s: ln s http://ww w .dickso n-compute r.com /w sd l/WorkflowVie ws u pp r e ss J o in.. . yesp a r t n e r L in k s

p a r tn e r L i n k (2)n a m e p a r t n e r L i n k T y.. . m y R o l e p a r t n e r R o l e

1 intelligenceBurea u lns:intelligenceBureauL inkTyp e

intelligence Service

2 cityBank lns:cityBankLink Type bankServic ev a r i a b l e sf l o w

n a m e contro l-flowli n k sr e c e i v e

n a m e Star tp a r t n e r L i n k intelligenceBurea up o r t T y p e ini tialize PTo p e r a t i o n initializ ev a r i a b l e requestc r e a te I n s ta n c e yess o u r c e linkNam e= initialize d

i n vo k e (4)n a m e p a r tn e r L in k p o r t T y p e o p e r a t i o n i n p u t V a r i a b l e ou tp u t V a r i a b le ta rg e t s ou r c e

1 IDChec k intelligenceBurea u lns:readP T rea d request key s ta rg e t linkNam e... s ou r c e (3)li n k N a m e

1 keys-ID -to-bank2 keys-ID -to-crim e3 keys-ID -to-border

2 Ban kChe ck cityBank lns:readP T rea d key s ta rg e t linkNam e... s ou r c e (1)3 CrimeChec k intelligenceBurea u lns:readP T rea d key s ta rg e t linkNam e... s ou r c e (1)4 BorderChec k intelligenceBurea u lns:readP T rea d key s ta rg e t linkNam e... s ou r c e (1)

r e p l yn a m e Endp a r t n e r L i n k intelligenceBurea up o r t T y p e completeP To p e r a t i o n complet ev a r i a b l e resul tt a r g e t linkNam e=bank -endta r g e t linkNam e=crim e-endta r g e t linkNam e=border-end

f l o w nam e=semanti c- flowf l o w nam e=data- flowf lo w nam e=securi ty- flowf lo w nam e=exceptio n-flow

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WSDL Generation<definitions> <types> <!-- XML Schema --> </types> <message name=“ViewNFlowFRequest” /> <message name=“ViewNFlowFResponse” />… <portType name=“ViewNActivityMInterface”> <operation name=“ViewNFlowF”> <input message=“ViewNFlowFRequest” /> <output message=“ViewNFlowFResponse” /> </operation> … </portType> …<binding name=“ViewNActivityMBinding” type=“ViewNActivityMInterface”> <soap:binding transport=“http://schemas.xmlsoap.org/soap/http” />…</binding>…<service name=“WfviewN”> <port name=“WfviewNActivityMPort” binding=“WfviewNActivityMBinding”> <soap:address location=“http://dept.gov.hk/ServicesS/ViewN” /> </port> … </service></definitions>

Process View -> WSDL service

Activity -> WSDL port

Flows -> WSDL operation

Messages -> WSDL bindings

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Basic WSDL for the process view of the ID service to the Customs

Name: ID Check ServiceLocation/Provider: Immigration Department<!-- Control Flow --!>+Port 1 - Input: Batch ID Approval Request

* User Name * User Organization

* Suspect Names* Request Reason

- Output: Approval Message/Rejection Message* Request Status

(Approved/Rejected)* Security Token (if approved)

<!-- Data Flow --!> + Port 2 - Input: Single ID Request

* Suspect Name * Suspect Description

- Output: Basic ID Information/Error Message* Suspect ID

* Suspect Birthday * Suspect Phone

Number* Suspect Address …

+ Port3 - Input: Single Extended ID Request … - Output: Extended ID Information/Error Message…

+ Port 4 - Input: Batch ID Request …+ Output: Batch Suspect Analysis Report (with ID information) …

<!—Security Flow --!> + Port 5 - Input: Any Government Department Security

Token- Output: Accept Message/Rejection Message

+ Port 6 - Output: Batch ID Token + Port 7 - Input: Batch ID Token

- Output: Accept Message / Rejection Message…<!—Exception Flow --!> + Port 8 - Output: ID Not Found Exception+ Port 9 - Output: Analysis Error Exception+ Port 10 - Output: Token Invalid Exception/Security

Alert Exception…

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Integration for the Suspect Investigation Service

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Data Schema in OWL<owl:Ontology rdf:about="#Identity"> <owl:versionInfo>v 1.00 2003/12/16 22:37:39</owl:versionInfo> <rdfs:comment>An example OWL ontology for Identity</rdfs:comment> ... <owl:Class rdf:ID="DataSchema"> <owl:unionOf rdf:parseType="Collection"> <owl:Class rdf:about="#id-no"/> <owl:Class rdf:about="#name"/> <owl:Class rdf:about="#sex"/> <owl:Class rdf:about="#date-of-birth"/> <owl:Class rdf:about="#area-code"/> <owl:Class rdf:about="#phone-no"/> <owl:Class rdf:about="#address"/> <owl:Class rdf:about="#postal-code"/> <owl:Class rdf:about="#tax-file-no"/> </owl:unionOf></owl:Class> ...</owl:Ontology>

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Simplified BPEL Code for Semantic Flow

<flow name="semantic-flow"> <ontology activityName="IDCheck"> <ontologyRef="http://www.example.org/identity.owl" /> </ontology> <ontology activityName="BankCheck"> <ontologyRef="http://www.example.org/banking.owl" /> </ontology> <ontology activityName="CrimeCheck"> <ontologyRef="http://www.example.org/legal.owl" /> </ontology> <ontology activityName="BorderCheck"> <ontologyRef="http://www.example.org/custom.owl" /> </ontology> …</flow>

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BPEL Assertions for Data Flows <flow name="data-flows"> <integrate name="data-flow-1"> <dataset name="IDrecord"> <attributes name="id-no"

key="primary"/> <attributes name="sex"/> <attributes name="age"/>

... </dataset> <dataset name="CrimeRecord" <attributes name="id-no"

key="primary"/> <attributes name="crime-description"/> <attributes name="sentence"/>

... </dataset> <dataset name="BorderRecord" <attributes name="id-no"

key="primary"/> <attributes name="entry-or-exit"/> <attributes name="place"/> <attributes name="date"/>

... </dataset> </integrate>

<integrate name="data-flow-2"> <dataset name="CrimeRecord" <attributes name="id-no" key="primary"/> <attributes name="crime-description"/> <attributes name="sentence"/> ... </dataset> <dataset name="BorderRecord" <attributes name="id-no" key="primary"/> <attributes name="entry-or-exit"/> <attributes name="place"/> <attributes name="date"/> ... </dataset> <dataLinkage name="IDrecord"> <attributes name="id-no" key="foreign"/> <attributes name="tax-file-no"

key=foriegn"/> <dataLinkage/> <dataset name="BankRecord" <attributes name="tax-file-no"

key="primary"/> <attributes name="bank-no"/> <attributes name="account-no"/> <attributes name="transaction"/> ... </dataset> </integrate></flow>

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Security Token Example<S:Envelope xmlns:S="http://www.w3.org/2001/12/soap-envelope" xmlns:wsse=http://schemas.xmlsoap.org/ws/2002/04/secext

xmlns:wii="http://schemas.workflow.org/wii/2003/12/authentication">

<S:Header> ... <wsse:Security> <wsse:UsernameToken> <wsse:Username>93856543</wsse:Username> <wsse:Password>3875</wsse:Password> <wii:SubjectName>Sherlock Holmes</wii:SubjectName> <wii:SubjectDepartment>Police</wii:SubjectLocation> </wsse:UsernameToken> </wsse:Security> ... </S:Header> ...</S:Envelope>

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Simplified BPEL Code for Security Flows

<flow name="security-flow">

<sessionStart>generateSecurityToken</sessionStart>

<clearance activityName="IDCheck">

<securityToken required="True"> <tokenType>SAML</tokenType> <securityToken/> </clearance> <clearance

activityName="BankCheck"> <securityToken required="True"> <tokenType>SAML</tokenType> <securityToken/> </clearance>

<clearance activityName="CrimeCheck">

<securityToken required="True"> <tokenType>SAML</tokenType> <securityToken/> </clearance> <clearance

activityName="BorderCheck" <securityToken required="True"> <tokenType>SAML</tokenType> <securityToken/> </clearance>

<sessionEnd>revokeSecurityToken</sessionEnd>

</flow>

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Exception Flows and SOAP Fault

Workflow Layer

exception-flows

control-flowsdata-flows

security-flows

event

erro

r

interaction

acti

on

SOAP Message

SOAP Fault

BPEL4WScondition

orchestration

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BPEL Assertions for Exception Flow

<flow name="exception-flow"> <exceptionHandling name="rule-1"> <event>anyActivitySpecificException</event> <condition>affectDataIntegration</condition> <action>remedyOrforwardRecoveryProcedure</action> </exceptionHandling> <exceptionHandling name="rule-2"> <event>anyCrossActivityException</event> <condition>affectDataLinkage</condition> <action>backwardRecoveryProcedure</action> </exceptionHandling> <exceptionHandlingDefault> <action>abortControlFlow</action> </exceptionHandlingDefault></flow>

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Conclusions New perspective of process views through a subset

of various flows of original workflow Process views are now enriched with the support of

data flow, semantics flow, exception flow, and security flow

Systematic design of process views for better B2B interaction

Especially useful for large-scale information systems

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Future Work

Focus on the scalability and reusability of BPEL4WS Wait for a WFMS to support BPEL4WS effectively

and efficiently Study focus on semantic help on exception

handling Privacy-flow Conflicts between flows Alerts and flow urgency Requirements engineering