Lecture Building reliable component-based systems - Chapter 18: A framework for integrating business applications

Chapter 18
A Framework for Integrating Business
Applications

Building Reliable Component­based 


Overview
Motivation
Information Organizer
Practical Experiences

Building Reliable Component­based 


Motivation
All information of importance is to be made available to
different categories of users.
Containing information which must be reused.
Another method to access and interrelate associated
information in different systems is called for.
Microsoft’s Active Directory: a tool for sharing
information between different applications.
IEC1346, OMG, IT4
Aspects, Objects

Building Reliable Component­based 


Information Organizer
A product for integration of systems

Focuses on information systems
Introduces new concepts
Objects
Aspects
Reuse!

Building Reliable Component­based 


Introduction, cont.
Reuse of legacy systems
Data
Applications
Application patterns
Another possibility of reuse

Building Reliable Component­based 


Technical details
Builds on Microsoft technologies
Windows 2000
COM
Active Directory
Security
Reuse again!

Building Reliable Component­based 

Concepts
Business Object Model
The conceptual model
Contains definitions of concepts
Information Organizer
The application
Business Object Framework
The implementation of Business Object Model in
Information Organizer

Building Reliable Component­based 


Business Object Model
The conceptual model
Introduces new concepts
Objects
Aspects
Relations
Roles
Views

Building Reliable Component­based 


Objects
The most central type of entity in the model
Objects model physical or logical objects
Represent entities in the applications to be integrated
E.g. “valve”, “pump”, “issue”, “workflow step”.

Little functionality in itself - related data is carried by its
Aspects
Aspect

Aspect

Aspect

Object

Aspect

Building Reliable Component­based 


Aspects
Contains part of the functionality of an object
Often contain documents of some kind
Are often associated with (legacy) applications
Can be added and removed dynamically
New types of aspects can be added when the system is
ready to handle them

Aspect

Aspect

Object

Aspect

Aspect

Building Reliable Component­based 


Relations
Objects exist in relation to other objects
Typed or generic relations
Allow connection of objects with certain aspects
New types can be defined
Used to structure the objects
Trees
Arbitrary structures
Can be interpreted by a user or the system itself
Object

Object

Building Reliable Component­based 


Roles
A certain function offered by an object
Implemented by aspects
Not very clear description

Building Reliable Component­based 

Views
Limits the visibility
Objects, aspects, and relations
Different categories of users
Different information interesting depending on context
Possibility to switch views
The selected item still in focus
E.g. locate an issue in a personal view, then switch to
workflow view
Can be added dynamically

Building Reliable Component­based 


Business Explorer

Presentation layer
System-wide information model

Application
specific
user interface

Integration layer

Data/application
layer
Issue management system

Document management system

Building Reliable Component­based 

CAD system


Business Object Framework
The implementation of Business Object Model
The “core” of Information Organizer
Examples of tools and functions
Generic implementation of Aspects, Objects etc.
Configuration environment
Development environment
Runtime environment
Mechanisms for defining object and aspect types
Implement certain COM interfaces

Building Reliable Component­based 


Information Organizer
Conventional three-layered architecture
User interface layer (three types)
Business Logic layer (Business Object Framework)
Data layer
Applications
Documents
Databases

Three types of user interfaces available

“Thin” client – standard browser
“Fat” client – installed code on client machines
“Ultra-thin” client – WAP client

Building Reliable Component­based 


Information Organizer, cont.

Building Reliable Component­based 


Application Patterns
Generic implementations of commonly occurring
patterns
Non-domain specific patterns
Three patterns are described
Business Process Support, “workflow”
Document Management Support
Relational Database Connector
Applied on Information Organizer level
No support needed from participating applications

Building Reliable Component­based 


Business Process Support
Adding “workflow” concept to systems
Configuration
Runtime support

New object, aspect, and relation types
Processor
Process
Process Flow
Target
“Above” original application level

Building Reliable Component­based 


Business Process Support, cont.

Building Reliable Component­based 


Document Management Support
Creates documents “on the fly”
Uses templates
Inserts data from objects
Designed for Internet
Integrated with archive system

Building Reliable Component­based 


Relational Database Connector
A means of retrieving data from a standard database
Generic implementation
Builds on XML
Separates data from presentation

Each data row is represented by an object in BOF
Data still resides in the database
Security on row level

Building Reliable Component­based 


Relational Database Connector, cont.
Data
Description of data records
Information whether some data items are writeable
Presentation
Presentation format

Building Reliable Component­based 


Practical Experiences
Component based development can be highly
profitable.
A significant part of the development time was spent in
learning the full capabilities and impacts of existing
technologies and components.
Development of custom functions for the framework
actually occupied a smaller part of the total project time.
One of the main reasons why verbal commitments to
component-based development often fall short in
practice.

Building Reliable Component­based 

A three layered implementation architecture
UI

UI

Business

BO

Aspect

DS

Data

UI

UI

UI

WebCam

Word

File

File

Relations
Properties
Camera
Help
Change
Services
Delete

DS = Data Storage
UI = User Interface
BO = Business Object
Dll = Dynamic linked library

UI

UI

Business

BO

Data

UI

UI

Aspect

DS

dll

DB
File

UI

Notepad

File

Building Reliable Component­based 

Relations
Properties
MyService
Notepad
Change
Services
Delete