Distributed, Collaborative Processing System

(COBRA Virtual Office)

Distributed, Collaborative

Processing Systems –Some Prospects

E-Commerce

B2B and B2C

-Collaborative Product design

-Collaborative Product decision

Software Engineering Environments

-Distributed Collaborative system design space

Group communication

-Net meeting

-PDA, PCS etc

-Virtual class rooms

Personal entertainment

-On-line video games

Multiple users at different locations can work on one design collaborativelyand simultaneously. No travel and no delay.

Higher Productivity,Lower cost,Better Traceablity.

COBRA= Collaborative behavioral Requirement and Architecture

FOR

• Modeling requirements• Designing architecture • Evaluating existing architectures/components if they can meet new requirements•Monitoring projects

The System Provides

• Communication of Knowledge

• Simulation

• Project Management

• Traceability

History of COBRA

• Started in 1994 as a research prototype

• Initial implementation in c/c++ and tc/tlk

• Current implementation in Java

Main Challenges seen previously

• Poor documentation of the system

• Insufficient communication when projects passed from semester to semester.

• Poor communication among members resulting in integration problem

•Reinventing the wheel due to poor code comments.

The system is implemented using Java/JavaBeans so as to enhance platform-independence, interoperability, composability (plug-and-play), and distributability.

Platform Independency

The system will be used to model the behavior of a variety of system types, including a mobile communication system.

Hence, we will be using a particular scenario for the particular system chosen to be modeled.

System Applications

Usecase for COBRA system

<<Uses>>

<<Uses>> <<Uses>

> <<Uses>>

<<Uses>>

<<Uses>>

<<Extends>>

<<Extends>>

<<Uses>>

<<Extends>>

<<uses>>

TCP/IP connection

<<uses>>

<<Extends>>

<<Uses>>

<<Uses>>

<<Uses>>

<<Uses>>

<<Uses>.

<<Uses>> <<Uses>

> <<Uses>>

<<uses>>

TCP/IP Connection

TCP/IP connection

<<Extends>>

User 2 Site, participant & Collaboration coordinator

Site 1 Particiapant & Collaboration Intiator Site 3

Particpant COBRA GUI Application

COBRA GUI application

COBRA System

Public Window in use

Virtual Office_1

Check Prelimnary Collaboration Plan

Display work bordcasted to/from other users

Petri Net Application

CPM/PERT Chart Application Draw and simulate CPM/PERT Chart

Begin Collaboration

Private Window in use

Friend window in use

Display individual user's work separately

Track work Progress acitivty

Draw and Simulate Petri Net

Virtual Office_3

Start Collaboration

Negotatiate and resovle conflicts

Virtual Office_2

Terminate Collaboration

Register Participants

Detect and record conflicts

Monitor Collaboration acitivity

Participant 1 is a collaobrator who initates the collaboration seesion

The content of the COBRA system package for User 2 is the same as user 1. Omitted for diagram clarity purpose

Collaboration Coordinating System

Get consensus on work completion

Send Messages between participant and coordinator

Brodcast work to other users

Brodcast work to other users

The content of the COBRA GUI application package for User 2 is the same as user 1. Omit ted for diagram clarity purpose

COBRA System

Collaboration Coordinating System

The content of the collaboration coardination sysytem package for User 1 is the same as user 2. Omitted for diagram clarity purpose

COBRA System

Cobra Virtual Office Functionalities

• Constructing Augmented Petri-Net (FSM) for System Behavior Modeling

•Constructing PERT Chart for Project Scheduling and management

As a test-bed, we are working on the modeling and analysis of system behavior using Augmented Petri Net (APN), a formalism which is expressively more powerful than Finite State Machines.

Constructing Augmented Petri-Net

More about Augmented Petri-Net

A form of FSMs, first proposed by C. A. Petri in 1962 A notation for defining abstract concurrent processesPrimitives:

Place

Transition

Token

TWhen all input places of a transition are enabled (i.e., with a token) and the external stimulus associated with the transition occurs, the tokens move from the input places to output places

Fundamental notions: Sequencing

T2

T1

T2T1

Concurrency

T2

T3Synchronization

T1T3

ONTARIO

Site

TEXAS Site

NORTH CAROLINA

Site

Collaborative Processing (view from Texas)

Public Window

S 1

S 1 2

T 1 1

T 1

T 1 3

S22

S 1 3 T 1 2

S 1 4

S 2 1 T 1 4 T 2 0

S 2 0

S 2

TX Window

 

S 1

T 1

T 1 3

S22

T 1 4

S 2

Collaborative Processing (view from Ontario)

Public Window

S 1

S 1 2

T 1 1

T 1

T 1 3

S22

S 1 3 T 1 2

S 1 4

S 2 1 T 1 4 T 2 0

S 2 0

S 2

ON Window

S 1 2

T 1 1 S 1 3

T 1 2 S 1 4

Collaborative Processing (view from North Carolina)

Public Window

S 1

S 1 2

T 1 1

T 1

T 1 3

S22

S 1 3 T 1 2

S 1 4

S 2 1 T 1 4 T 2 0

S 2 0

S 2

NC Window

S 2 1 T 2 0 S 2 2

Simulation

The system’s simulation functionality represent the behavior of Petri-net

Simulation (Cont’)

Another Aspect of the Virtual Office

Monitoring and Scheduling Projects Using PERT Chart

Why Do We Need PERT Chart

• Allows users to express time dependencies for project tasks

• Analyze the project critical path

• Tracks project progress to ensure that delay is recognized

• Provides a road map for a project manager

How to Represent a PERT Chart in How to Represent a PERT Chart in This SystemThis System

• The COBRA Virtual Office has functionality of constructing Augmented Petri-Net (APN), and allows system behavior simulation

• Traditional PERT Chart representation lacks dynamic functionality to monitor project progress

• A mapping from PERT chart to Augmented Perti-Net is proposed for the ease of project progress simulation

Figure 1: PERT Chart

Representation

•Numbered rectangles are nodes that represent events or milestones

•Directional arrows represent tasks that must be completed sequentially

•Diverging arrow directions indicate possibly concurrent tasks

•Dotted lines indicate dependent tasks that do not require resources

1

2

3

4

5

6

7

8

9

10

11

Create Schedule

Buy Hardware

Programming

Installation

Test Code

Write Man

Conversion

Test System

Training User Test

10

20 20 10

5

15 15

5

5 10

An Example

•Numbered rectangles are nodes that represent states of a project

•Directional arrows represent moving from one state to another

•Vertical bars represent transitions from one state to another

1

1’

2

3

4

5

5’ 6

7

8

9

10

11

Schedule done

@now>=t0+9 ۸ ~done /reminder

Hardware bought

@now>=t0+4 ۸ ~done /reminder

Programming done

@now>=t0+18 ۸ ~done /reminder

@now>=t0+13 ۸ ~done /reminder

Installation done

@now>=t0+13 ۸ ~done /reminder

man done

@now>=t0+4 ۸ ~done /reminder

conversion done

@now>=t0+4۸ ~done /reminder

Training

done@now>=t0+9 ۸ ~done /reminder

User test done

@now>=t0+18 ۸ ~done /reminder

Code test done

@now>=t0+9 ۸ ~done /reminder

system test done

Figure 2: APN

Representation

An Example (Cont’)

COBRA architecture

APN/Pert Chart Applications

GU Interface

Repository

Collaborator

Tutor

COBRA System Client-Server

Model constructor

Scenarios Models File Manager Simulator

Negotiator Utilities GUI Basic GUI

Animator

Client –Server Communicator

Configuration Manager

Animator

Simulator Integrator

Figure 4.1 Client-Server architecture for COBRA System

Explanation for symbols: 3D gray circle represents the COBRA system either a client or server Cleared Circles represent main components Rectangles represents sub-components Note : Detail description for each sub-components are illustrated on the following pages.