a three-tier view-based methodology for m-services adaptation

1

A Three-tier View-based Methodology

for M-Services Adaptation

Eleanna Kafeza

Department of Marketing and Communications, Athens University of Economics &

Business [email protected]

S.C. Cheung

Dept. of Computer Science

Hong Kong University of Science & Technology

[email protected]

Dickson K.W. Chiu

Senior Member, IEEE

Ho-fung Leung

Dept. of Computer Science & Engineering

Chinese University of Hong Kong

[email protected]

Dickson Chiu et al. TSMC 2003 3-Tier View Adaptation - 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


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.


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


A Process for Service Negotiation

User inputs request with

service options

Send options to

user

User evaluates options [with feasible options]

[without feasible options]Reply

YES/NO for each option

ReplyCounter Options

ReplyConstraints

Evaluate constraints and options

Informchosen details

[good option found]

[max round not exceeded]

[max round exceeded]

Informfailure

[passive mode]

[constraint mode]

[counter-offer mode]

Service Provider User

[no option found]

Receive servicedetails


User Features on Different Platforms

User Platforms

Functions

Application Server (B2B)

PDA WAP Phone Messaging Device

Service Request

Web Service

Browser interface or programmed action

WAP interface SMS/EMS

Alerts Web Service

ICQ, email (or SMS if user also accessible)

SMS/EMS

Exception Handling

Web Service and /or email

Browser interface

WAP interface SMS/EMS

User Response Mode

Passive, Counter-offer, Constraint

Passive, Counter-offer, Constraint

Passive, Counter-offer

Passive


3-tier View Architecture

Begin CheckParts Info

PrepareQuotation

PrepareExtra Info

OrderMissing

Parts

ServicePrepara-

tion

BeginParts

QuotationDeliverParts End

End-User

System Integrator

Parts Vendor

Deliver &Install

End

BeginQuotationEnquiry

QuotationEvaluation

PurchaseOrder

Check &ReceiveSystem

PaymentAuthori-zation

End

BeginAssemble

SystemInstall

SoftwareSystemTesting End

Service Preparation

Qu

ota

tio

n

AND

AND

AND

AND

AND

AND

AND

Verify &Confirm

DBMS

User Interface Views

BeginCheck

Parts InfoPrepare

QuotationPrepare

Extra Info

OrderMissing

Parts

ServicePrepara-

tion

BeginParts

QuotationDeliverParts

End

End-User

System Integrator

Parts Vendor

Deliver &Install

End


QuotationEvaluation

PurchaseOrder



End

BeginAssemble

SystemInstall

SoftwareSystemTesting

End

Service Preparation

Qu

ota

tio

n

AND

AND

AND

AND

AND

AND

AND

Verify &Confirm

Begin CheckParts Info

PrepareQuotation

PrepareExtra Info

OrderMissing

Parts

ServicePrepara-

tion

BeginParts

QuotationDeliverParts End

End-User

System Integrator

Parts Vendor

Deliver &Install

End


QuotationEvaluation

PurchaseOrder



End

BeginAssemble

SystemInstall

SoftwareSystemTesting End

Service Preparation

Qu

ota

tio

n

AND

AND

AND

AND

AND

AND

AND

Verify &Confirm

Process Views

SMS dialogue presentation

Simplified workflow steps and proceduresWorkflow View

Highly summarized and mandatory information as message content

Mandatory fields only

Highly summarized information

Omit some fields

Summarized informationData View

SMS message presentation

WML translation

Highly reduced screen

Simplified screen layout

Low resolution graphics

Panning and Zooming

User Interface View

SMSWAPPDAPlatforms

Views






Omit some fields



WML translation




Panning and Zooming

User Interface View

SMSWAPPDAPlatforms

Views






Omit some fields



WML translation




Panning and Zooming

User Interface View

SMSWAPPDAPlatforms

Views






Omit some fields



WML translation




Panning and Zooming

User Interface View

SMSWAPPDAPlatforms

Views






Omit some fields



WML translation




Panning and Zooming

User Interface View

SMSWAPPDAPlatforms

Views






Omit some fields



WML translation




Panning and Zooming

User Interface View

SMSWAPPDAPlatforms

Views

Data Views

PDA memory

SMS Gateway

WAPGateway

Web Server

Internet Messenger

Users

Processes of Other Organizations

Service Process


Meta-model for 3-tier Views

**

UserInterface

View

Screen/ Form

ProcessView

DataView

*

* *

*

**

*

Table*

*

* *

* Task

*

*

many to many association

aggregation association

WAP UserProcess

View

SMS UserProcess

View

Web UserProcess

View

inheritance

Role

**

User

* *

Process

*

1

*

**

transition

Agent / B2BProcess

View


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.


Contribution of 3-Tier Views toDifferent Platforms

User Platforms

Views

Application Server (B2B)

PDA WAP Phone

Messaging Device

User Interface View

Web Service interface for programmed interactions

Simplified screen layoutLow resolution graphicsPanning and zooming

WML translationHighly reduced screen


Data View Mutually agreed schema and semantics for interoperation

Omit some fieldsSummarized information

Mandatory fields onlyHighly summarized information


Process View

Cross-organizational process interoperation

Simplified process steps and procedures



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


Capabilities Required by Various Process Activities

Activity

Capability

User evaluates options

Reply Y/N for each option

Reply constraints

Reply counter options

Receive service details

Authentication required required required required required

Message handling

required not required not required not required required

Message confirmation

not required required not required not required not required

Formatted data handling

not required not required not required required not required

Constraint editornot

required not required required not required not required

Real-time response

not required not required not required required not required


Features supported byVarious Platforms

PlatformProvided Feature

B2B PDA WAP SMS

Deployment of User applications

yes yes no no

Client-side SSL certification yes no no no

Form handling yes yes yes no

Message Reception yes yes yes yes

Message Authoring yes yes yes yes

Message Transmission yes yes yes yes

Real-time interactions yes yes yes no

Message size large large medium short


Meta-model for Matching Features Against Capabilities

Platform

adapts

TargetProcess

ProcessView

Feature

offers*

1..*

FeatureSet Capability

Activity1..*

*requires

**

matches

*

*

**

Realization


Realization Table Matching Feature-Sets against Capabilities

Feature-Set Capability Remarks

{Deployment of User applications} Constraint editor Availability of a constraint editor with constraints

outputted according to a predefined XML schema.

{Client-side SSL certification, real-time interactions} Authentication Availability of a personal certificate.

{real-time interactions} Authentication Performs logon and logoff for each process view instance.

{real-time interactions} Real-time response

{Form handling, real-time interactions}

Formatted data handling

{Message Reception} Message handling

{Message Authoring, Message Transmission} Message confirmation

The feature that supports returning a received message is not generally available for roaming SMS services.

…


Process Views for Participants on Different Platforms

Receive alertmessage

Logon / refresh

[with feasible option] ReplyYES/NO for each option

Enter counter options

EnterconstraintsMessage

contains details

[passive mode]

[constraint mode]

[counter-offermode]

(b) Process View for PDA/Web Users

Display options

[meetingscheduled or canceled]

[meetingnot yet scheduled]

[without feasible option]

(a) Process View for B2B Interactions

Receive service options

Decide options


Replycounter options

ReplyconstraintsMessage

contains details

[passive mode]

[constraint mode]

[counter-offermode]

[servicescheduled or canceled ]

[service optionsnot yet agreed]

[without feasible option]

Decide responseMode

Enter responseMode


Message contains details


(c) Process View for WAP User

(d) Process View for SMS User


Logon / refresh


Enter counter options

Message contains details

[passive mode]

[counter-offermode]

Display options


[meetingnot yet scheduled] [without

feasible option]

Enter responseMode

ReplyYES/NO for each option

[meetingnot yet scheduled]


User Interface Views

for PDA users for WAP users

scroll down


User Interface Views Supporting the “Display Options” for WAP Users

select View Request

select available time slots

select the next option

scroll down

…

continue until the

last option

viewing the first option

select finish


User Interface Views Supporting the “Enter Counter Options” for WAP Users

No available time slots

were selected in all options

finish with no available time slots in any options

select YES for counter offer

response mode

select time slots

enter venue and date


User Interface View Implementation

ActivityActivity

XMLProcessor

XML Document Object

Screen / Form Activity

PresentationObject

XSL Style SheetXML Schemas

User Inputs

User Interface View Workflow View

XML Service Object and WAP Listing

<?xml version=”1.0” encoding=”ISO-8859-1”?><Proposal id=”mtg-fkn-01”> <description>Service Options.</description> <date>May 30</date> <time>14:00</time> <Proposer> <name>Franklin</name> <affiliation>CUHK</affiliation> </Proposer> <Option> <venue>Conference Room, 3/F, CUHK, Shatin</venue> <TimeSlot> <date>Jun 1</date> <startTime>9:00</startTime> <endTime>9:30</endTime> <status>Unconfirmed</status> </TimeSlot> <TimeSlot> <date>Jun 1</date> <startTime>9:30</startTime> <endTime>10:00</endTime> <status>Unconfirmed</status> </TimeSlot> </Option> ...</Proposal>

<?xml version="1.0"?><!DOCTYPE wml PUBLIC "-//WAPFORUM//DTD WML

1.1//EN""http://www.wapforum.org/DTD/wml_1.1.xml"><wml> <card id="start" title="Option Details"> Venue: Conference Room, 3/F, CUHK,

Shatin Select Available Time Slots: <select name="slot1"> <option value="NULL">SLOT 1</option> <option value="0900">JUN 1 (9:00-9:30)</option> <option value="0930">JUN 1 (9:30-10:00)</option> <option value="0930">JUN 1 (10:00-10:30)</option> <option value="0930">JUN 1 (10:30-11:00)</option> <option value="0930">JUN 1 (11:30-12:00)</option> </select> ... </card></wml>


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


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.

Constraint Satisfaction Problem (CSP)

Variables:Day, Time, Place

Domains:D(Day) = {Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday}D(Time) = {9am, 9:15am, 9:30am, …, 11:45pm, 12:00am}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 = {<Monday, CUHK>, <Monday, HKUST>, <Monday, HKU>, <Tuesday, CUHK >, <Tuesday, HKUST>, <Tuesday, HKU>, <Wednesday, CUHK >, <Wednesday, HKUST>, <Thursday, CUHK >, <Thursday, HKUST>, <Thursday, HKU>, <Friday, CUHK >, <Friday, HKUST>, <Friday, HKU>, <Saturday, CUHK >, < Saturday, HKUST>, < Saturday, HKU>, <Sunday, CUHK >, < Sunday, HKUST>, < Sunday, HKU>}Time-Place-Requirement = {<9am, CUHK>, <11am, HKUST>, <2pm, HKU>}


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

Implementation Architecture

Web / WAP Access

XSLT ProcessorWeb Front-end

Web Services Programmatic

Access

Public UDDIRegistryEnterprises

User-Side

Views & Stylesheets Repository

<<session bean>>

ServerProcess<<session bean>>

ProcessView

ApplicationSubsystem

ConsistencyChecker

View and Stylesheet Editor

ViewMaintenance Subsystem

View Specifications in XML

XSLT Stylesheets

End users on Multi-platformDevices

Server-SideSMS Entity

Adapter

<<entity bean>>

Data ViewEnterprise Data

ProcessSpecification andCapability Editor

publish

EJBContainer

WebContainer

Web Service

Interface

<<session bean>>

ConstraintSolver

External InterfaceSubsystem


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)


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

a three-tier view-based methodology for m-services adaptation

Documents

design process views

process view mechanism

workflow views

tier viewbased support

tier viewbased methodology

base process

tier view conference

design data views