ComponentBased Software Development: Technologies, Quality Assurance Schemes, and Risk Analysis Tool

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Component-Based Software Development
Technologies, Quality Assurance Schemes,
and Risk Analysis Tools
Cai Xia Supervisor Prof. Michael R. Lyu
Markers Prof. Kam-Fai Wong Prof. Ada Fu
December 18, 2000
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Presentation Outline
? Introduction ? Current component technologies
? Quality assurance issues and a QA model for
Component-Based Software Development (CBSD) ? A
risk analysis tool ARMOR ? Expected new features
of our risk analysis tool ? Demonstration of
ARMOR ? Conclusion and future work
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Introduction
? Software systems become more and more
large-scale, complex and uneasily controlled ?
One of the most promising solution now is
component-based software development approach ?
The process of CBSD is totally different from
traditional systems ? Quality Assurance is very
important for component-based software systems
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What is Component-Based Software Development?
Software systems can be developed by selecting
appropriate off-the-shelf components and then
assembling them with a well-defined software
architecture.
Component repository
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Advantages of CBSD

• Reduce
• Development cost
• Time-to-market
• Improve
• Maintainability
• Reliability
• Overall quality of software systems

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What is A Component?
? A component is an independent and replaceable
part of a system that fulfills a clear function ?
A component works in the context of a
well-defined architecture ? It communicates with
other components by the interfaces
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System Architecture
? Layered ? Modular
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Current Component Technologies

• ? Common Object Request Broker Architecture
  (CORBA) from Object Management Group (OMG)
• ? Component Object Model (COM) and Distributed
  COM (DCOM) from Microsoft
• ? JavaBeans and Enterprise JavaBeans (EJB)
  from Sun Microsystems

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CORBA

• ? CORBA is an open standard for application
  interoperability
• ? Allows applications/components to communicate
  with one another despite of different locations
  and designers.
• ? The interface is the only way that
  applications/ components communicate with each
  other.
• ? Object Request Broker (ORB) is the middleware
  that establishes the client-server relationships
  between components.
• ? CORBA is widely used in OO distributed systems
  including component-based software systems

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COM/DCOM

• ? COM is a general architecture for component
  software
• Defines how components and their clients interact
  directly and dynamically
• ? DCOM is a protocol that enables software
  components to communicate directly over a network
• ? Designed for use across multiple network
  transports, including Internet protocols such as
  HTTP

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JavaBeans/EJB
? JavaBeans for client-side component
development, while Enterprise JavaBeans for
server-side component development ? Offers an
efficient solution to the portability, security
and reliability of component-based development. ?
The features are well suited for developing
robust server objects independent of OS, Web
servers and database management server.
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Comparison of Current Component Technologies
 
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Life Cycle of CBSD
? Requirements analysis ? Software architecture
selection, creation, analysis and evaluation ?
Component evaluation, selection and
customization ? Integration ? Component-based
system testing ? Software maintenance
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QA for Component-Based Software
Two inseparable parts ? How to certify
quality of a component? ? How to certify
quality of a component-based software
system? Metrics for components ? Size
? Complexity ? Reuse frequency ?
Reliability
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A Quality Assurance Model for CBSD
? Component ? System
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Hong Kong SQA Model

• Proposed by Hong Kong Productivity Council
• Provides the standard for local software
  organizations
• Meet basic software quality requirements
• Improve on software quality practices
• Use as a bridge to achieve other international
  standards
• Assess and certify them to a specific level of
  software quality conformance

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Main Practices
Requirement Analysis
Component
Architecture Design
System
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Process Overview ? Component Requirement Analysis
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Process Overview ? Component Development
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Process Overview ? Component Certification
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Process Overview ? Component Customization
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Process Overview ? System Architecture Design
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Process Overview ? System Integration
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Process Overview ? System Testing
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Process Overview ? System Maintenance
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The Feature of Our QA Model
Compared with other existing models ? Simple,
easy to apply ? Design for local component
vendors (small to medium size) ? Focused on
development process, according to the life cycle
of CBSD ? Not focused on the measure/predict the
quality of components/systems
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ARMOR Analyzer for Reducing Module Operation Risk
? The prototype was developed at Bell Lab in
1995. ? A software risk analysis tool which
automatically identifies the operational risks of
software program modules. ? Take data directly
from project database, failure database and
program development database. ? Collect software
metrics, select risk models, and validate the
established models.
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ARMOR Objectives
? To access and compute software data deemed
pertinent to software characteristics . ? To
compute product metrics automatically whenever
possible ? To evaluate software metrics
systematically ? To perform risk modeling in a
user-friendly and user-flexible fashion ? To
display risks of software modules ? To validate
risk models against actual failure data and
compare model performance ? To identify risky
modules and to indicate ways for reducing
software risks
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High Level Architecture for ARMOR
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Component Evaluation and Risk Analysis Tool

• ? Based on ARMOR
• ? Add some Java feasure on it
• Java Classes
• Program Coupling
• Java Methods
• Hierarchical Structure
• Clone Detection

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Existing Metrics on Java

• ? Metamata
• ? Jprobe
• ? Both base on Java language
• ? Adopted in current component market

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Examples of Metamata Metrics
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Conclusion and Future Work
? We look at the current technologies, quality
assurance schemes for component-based software
development. ? Our work is to implement a
component evaluation and risk analysis tool ?
The tool will make use of the well-adopted
metrics ? It is Java language oriented.
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Q A