A Threetier Viewbased Methodology for MServices Adaptation

1
A Three-tier View-based Methodology for
M-Services Adaptation
S.C. Cheung Dept. of Computer Science Hong Kong
University of Science Technology scc_at_cs.ust.hk
Dickson K.W. Chiu Senior Member, IEEE

• Eleanna Kafeza
• Department of Marketing and Communications,
  Athens University of Economics Business
• kafeza_at_aueb.gr

Ho-fung Leung Dept. of Computer Science
Engineering Chinese University of Hong
Kong lhf_at_cse.cuhk.edu.hk
2
Motivation and Background

• Often we have existing systems
• Extend it to support programmatic interactions
  B2B / agent
• Extend/adapt it to support emerging mobile
  computing environment - SMS, WAP, PDA,
• Adapting human-agent collaboration system for
  mobile environment e.g., workforce management
• 3-tier architecture commonly adopted over Web
• Extend our Process View mechanism into 3-tiers
  for adaptation
• User Interface Views
• Process Views
• Database Views

3
Project Background

• B2B Process Views
• D.K.W. Chiu, S.C.Cheung, K. Karlapalem, Q. Li,
  Sven Till, and E. Kafeza. Workflow View Driven
  Cross-Organizational Interoperability in a Web
  Service Environment, Information Technology and
  Management, 5(3/4)221-250, 2004.
• D.K.W. Chiu, K. Karlapalem, Q. Li and E. Kafeza.
  Workflow Views Based E-Contracts in a
  Cross-Organization E-Service Environment.
  Distributed and Parallel Databases
  12(2-3)193-216, 2002.
• 3-tier View conference paper
• D.K.W. Chiu, S.C. Cheung and E. Kafeza.
  Three-tier View-based Support for Mobile
  Workflow. First International Conference on
  Mobile Business, Athens, Greece, July 2002.

4
Advantages of Views

• Motivated by views in federated object databases
  / relational database
• Help balance trust and security
• Access in fully controlled manner
• Minimize modification of existing process for
  interoperability
• Interface with different organization with
  different views
• Fast and manageable development
• Process Views as the center mechanism

5
A Process for Service Negotiation
6
User Features on Different Platforms
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3-tier View Architecture
Processes of Other Organizations
PDA memory
Internet Messenger
SMS Gateway
Service Process
WAPGateway
DBMS
Web Server
Users
Process Views
Data Views
User Interface Views
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Meta-model for 3-tier Views

aggregation association
Data View

User
Table
many to many association




Role
transition







User Interface View
Process View
Task


Screen / Form





inheritance
1
WAP User Process View
SMS User Process View
Web User Process View
Agent / B2B Process View
Process
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Methodology Overview

• Identify target platforms and the set of
  activities to be possibly adapted in the base
  process.
• For each activity identified, elicit the
  capabilities required for enactment.
• For each target platform, enlist its provided
  features.
• Match capabilities against features.
• Decide which activities need adaptation. Design
  process views accordingly.
• Design data views for each of the data sources
  based on the requirements of the process views.
• Design user interface views based on platform
  dependent restrictions.
• Perform validation of view consistency.

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Contribution of 3-Tier Views toDifferent
Platforms
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Process View - Introduction

• Process view structurally correct subset of
  process definition
• Motivated by views in federated object databases
• Originally for B2B interoperating processes among
  (different categories of) business partners to
  authorize external access to process
• Same mechanisms now used for users of different
  platform access different subset of process

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Capabilities Required by Various Process
Activities
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Features supported byVarious Platforms
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Meta-model for Matching Features Against
Capabilities
adapts
Target Process
Process View

Platform
1..
offers
matches


Feature
Activity


1..
requires



FeatureSet
Capability
Realization
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Realization Table Matching Feature-Sets against
Capabilities
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Process Views for Participants on Different
Platforms
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User Interface Views
for WAP users
for PDA users
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User Interface Views Supporting the Display
Options for WAP Users
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User Interface Views Supporting the Enter
Counter Options for WAP Users
finish with no available time slots in any options
No available time slots were selected in all
options
select YES for counter offer response mode
enter venue and date
select time slots
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User Interface View Implementation
User Inputs
XML Document Object
Presentation Object
Activity
Activity
XML Processor
Activity
Screen / Form
User Interface View
Workflow View
XSL Style Sheet XML Schemas
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XML Service Object and WAP Listing

• lt?xml version1.0 encodingISO-8859-1?gt
• ltProposal idmtg-fkn-01gt
• ltdescriptiongtService Options.lt/descriptiongt
• ltdategtMay 30lt/dategt
• lttimegt1400lt/timegt
• ltProposergt
• ltnamegtFranklinlt/namegt
• ltaffiliationgtCUHKlt/affiliationgt
• lt/Proposergt
• ltOptiongt
• ltvenuegtConference Room, 3/F, CUHK,
  Shatinlt/venuegt
• ltTimeSlotgt
• ltdategtJun 1lt/dategt
• ltstartTimegt900lt/startTimegt
• ltendTimegt930lt/endTimegt
• ltstatusgtUnconfirmedlt/statusgt
• lt/TimeSlotgt
• ltTimeSlotgt
• ltdategtJun 1lt/dategt

• lt?xml version"1.0"?gt
• lt!DOCTYPE wml PUBLIC "-//WAPFORUM//DTD WML
  1.1//EN"
• "http//www.wapforum.org/DTD/wml_1.1.xml"gt
• ltwmlgt
• ltcard id"start" title"Option Details"gt
• ltpgtltbgtVenuelt/bgt Conference Room, 3/F, CUHK,
  Shatinlt/pgt
• ltpgtltbgtSelect Available Time Slotslt/bgtlt/pgt
• ltpgt
• ltselect name"slot1"gt
• ltoption value"NULL"gtSLOT 1lt/optiongt
• ltoption value"0900"gtJUN 1 (900-930)lt/option
  gt
• ltoption value"0930"gtJUN 1 (930-1000)lt/optio
  ngt
• ltoption value"0930"gtJUN 1 (1000-1030)lt/opti
  ongt
• ltoption value"0930"gtJUN 1 (1030-1100)lt/opti
  ongt
• ltoption value"0930"gtJUN 1 (1130-1200)lt/opti
  ongt
• lt/selectgt
• lt/pgt
• ...
• lt/cardgt

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Data View vs. Complete Schema(Mobile Meeting
Scheduler Example)
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Adaptation Consistency

• By event trace semantics
• Tracing the start and end event of each task
• Based on process algebra and automata theory
• Consistency of process view with respect to a
  process
• a process view V not exhibiting any event
  sequences where no corresponding ones are found
  in the base process H.

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Constraint Satisfaction Problem (CSP)

• Variables
• Day, Time, Place
• Domains
• D(Day) Monday, Tuesday, Wednesday, Thursday,
  Friday, Saturday, Sunday
• D(Time) 9am, 915am, 930am, , 1145pm,
  1200am
• D(Place) CUHK, HKUST, HKU
• Constraints
• SuitableTime(Time)
• SuitableTime(Day)
• SuitablePlace(Place)
• Day-Place-Requirement(Day, Place)
• Time-Place-Requirement(Time, Place)
• Plus other personal constraints on Time, Day and
  Place

• Extents of Constraints
• SuitableTime 9am, 11am, 2pm
• SuitableDay Monday, Tuesday, Wednesday,
  Thursday, Friday
• SuitablePlace CUHK, HKUST, HKU
• Day-Place-Requirement
• ltMonday, CUHKgt, ltMonday, HKUSTgt, ltMonday,
  HKUgt,
• ltTuesday, CUHK gt, ltTuesday, HKUSTgt, ltTuesday,
  HKUgt,
• ltWednesday, CUHK gt, ltWednesday, HKUSTgt,
• ltThursday, CUHK gt, ltThursday, HKUSTgt,
  ltThursday, HKUgt,
• ltFriday, CUHK gt, ltFriday, HKUSTgt, ltFriday,
  HKUgt,
• ltSaturday, CUHK gt, lt Saturday, HKUSTgt, lt
  Saturday, HKUgt,
• ltSunday, CUHK gt, lt Sunday, HKUSTgt, lt Sunday,
  HKUgt
• Time-Place-Requirement
• lt9am, CUHKgt, lt11am, HKUSTgt, lt2pm, HKUgt

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Adaptation Considerations for Constraint-Solving
Application

• Centralized open-calendar protocol not suitable -
  no privacy protection, too much unnecessary data
  is sent
• Passive mode - inefficient protocol but simple,
  least data sent, suitable for SMS users
• In between reply counter-option mode or reply
  constraints but more complicated user interface
  required
• All these can be translated into constraints and
  therefore into a standard CSP problem

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Implementation Architecture
Public UDDI Registry
Enterprises
End users on Multi-platform Devices
Web Services Programmatic Access
Web / WAP Access
User-Side
Server-Side
SMS Entity Adapter
Web Service Interface
publish
Web Container
External Interface Subsystem
View Maintenance Subsystem
XSLT Stylesheets
ltltsession beangtgt Process View
Views Stylesheets Repository
Application Subsystem
View Specifications in XML
Enterprise Data
EJB Container
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Conclusion

• A three-tier view-based methodology for adapting
  applications to support multiple platforms
• A novel approach of applying process views in
  adapting collaboration systems to a mobile
  environment
• Details on the technologies for supporting such
  adaptations
• Support for both human users and user delegated
  autonomous agents in a collaboration system
• Use of constraints to limit data exchange in a
  collaboration system to reduce bandwidth
  consumption for mobile users
• Demonstration of the applicability of our
  methodology in supporting flexible mobile
  collaboration systems through these features.
• Rapid development and deployment of E-commerce
  systems (reuse and modular design)

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Further and Ongoing work

• How do we design the views? Based on what?-
  Requirement engineering and e-Contracts
• e-Contract enactment
• e-Contract enforcement and exception handling
• e-Contract Templates
• e-Negotiation
• Flows and Views
• Real-life applications
• e-Marketplace, workforce management, logistics,
  CRM, etc.
• HCI Human-Computer Interaction
• m-Government service
• m-Tourism service
• Mobile workforce management, esp. for service
  outsourcing