Transcript 11. Building Information Systems

MODULE-3 : UNIT-11
PLANNING AND
ORGANIZING FOR
INFORMATION
SYSTEMS
DEVELOPMENT
12.1
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SMILE
“
Smile, it is the key that
fits the lock of everybody’s
heart”
12.2
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OBJECTIVES
• How could building a new system change
the way an organization works?
• How can a company make sure that the
new information systems it builds fit its
business plan?
• What are the steps required to build a new
information system?
• What alternative methods for building
information systems are available?
12.3
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MANAGEMENT CHALLENGES
• Major risks and uncertainties in
systems development
• Determining when new systems
and business processes can have
the greatest strategic impact
12.4
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SYSTEMS AS PLANNED ORGANIZATIONAL CHANGE
Systems Development and Organizational Change
• Automation: Speeding up performance
• Rationalization of procedures:
Streamlining of operating procedures
• Business process reengineering:
Radical design of business processes
12.5
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BUSINESS PROCESS REENGINEERING AND PROCESS
IMPROVEMENT
Business Process Reengineering / Redesign
• Reorganizes work flows, combining
steps to eliminate redundant paperintensive tasks
• Large payoff from IT investment if
processes are redesigned before
applying technology
12.6
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BUSINESS PROCESS REENGINEERING AND
PROCESS IMPROVEMENT
Steps in Effective Process Reengineering
• Senior management needs to develop broad
strategic vision
• Management must understand and measure
performance of existing processes as baseline
• Information technology should be allowed to
influence process design from start
• IT infrastructure should be able to support
business process changes
12.7
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OVERVIEW OF SYSTEMS DEVELOPMENT
Overview
Systems development :
• Activities that go into producing
information systems solution
Systems analysis :
• Analysis of problems that organization
aims to resolve using information
systems
12.8
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OVERVIEW OF SYSTEMS DEVELOPMENT
The Systems Development Process
12.9
Figure 12-5
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OVERVIEW OF SYSTEMS DEVELOPMENT
Overview
Feasibility study
• Determining achievability of solution
Establishing information requirements
• Stating information needs that new
system must satisfy
• Identifying who, when, where and how
components of information
12.10
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OVERVIEW OF SYSTEMS DEVELOPMENT
Systems Design
• Details how system will meet information
requirements as determined by systems
analysis
• Specifications for the system solution
• Should reflect user business priorities
and information needs
12.11
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OVERVIEW OF SYSTEMS DEVELOPMENT
Completing the Systems Development Process
Programming / Implementing
• Process of translating system specifications
into program code & procuring other
components & integrating
Testing
• Checks whether the system produces desired
results under known conditions
• Unit testing, system testing, acceptance
testing, test plan
12.12
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OVERVIEW OF SYSTEMS DEVELOPMENT
Completing the Systems Development Process
Conversion
• Process of changing from old system to
new system
• Strategies:
– Parallel
– Direct cutover
– Pilot study
– Phased approach
12.13
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OVERVIEW OF SYSTEMS DEVELOPMENT
Completing the Systems Development Process
Production and maintenance
• Production is stage after new system is
installed and the conversion is complete
• Maintenance is changes in hardware,
software, documentation, or procedures of
production system to correct errors
12.14
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ALTERNATIVE SYSTEMBUILDING APPROACHES
Traditional Systems Lifecycle
Systems lifecycle
• Traditional methodology for
developing information system
• Partitions systems development
process into formal steps / stages
that must be completed sequentially
12.15
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SYSTEM DEVELOPMENT LIFE CYCLE
(SDLC)
SYSTEM
STEP 1
UNDERSTANDING
STEPS INVESTIGATION
CONCEPTUAL
DESIGN
STEP-2
SYSTEM
ANALYSIS
DEVELOP
STEP-3
SYSTEM
DESIGN
IMPLEMENT
STEP-4
MAINTAIN
12.16
STEP-5
DETAILED
DESIGN
SYSTEM
IMPLEMENTATION
SYSTEM
MAINTENANCE
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SDLC : STEP-1 : SYSTEM INVESTIGATION
1. Product : Feasibility Study Report
2. Activities :
– Determine whether a business problem
or opportunity exists.
– Conduct feasibility study to determine
whether a new or improved information
system is a feasible solution
– Develop a project plan and obtain
management approval.
12.17
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SDLC : STEP-1 : SYSTEM INVESTIGATION
(contd.)
12.18
3.
•
•
•
•
Feasibility Studies :
Organizational feasibility,
Economic feasibility,
Technical feasibility,
Operational feasibility
4.
•
•
•
•
Cost-benefit Analysis :
Tangible benefits.
Intangible benefits
Costs
Compare cost with benefits
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SDLC : STEP-2 : SYSTEM ANALYSIS
1. Product : Functional Requirements
2. Activities :
(a) Analyze the following : Information needs of end users,
 Organizational environment,
 Any system presently used,
(b) Develop the functional requirements of a
system that can meet the needs of end
user
3. Identify what is to be done and not how it is
to be done
12.19
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SDLC : STEP-3 : SYSTEM DESIGN
1. Product : System Requirements Specifications
2. Activities :
(a) Develop specifications for the : Hardware,
 Software,
 People,
 Network
 Data sources,
(b) Develop the information products (report
formats etc) that will satisfy the functional
requirements of the proposed system.
12.20
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SDLC : STEP-4 : SYSTEM IMPLEMENTATION
1. Product : Operational System
2. Activities : Acquire (or develop) : Hardware, Software, People,
Network, Data sources,
 Integrate and test the system
 Train the people to operate and
use it,
 Convert to new system
12.21
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SDLC : STEP-5 : SYSTEM
MAINTENANCE AND REVIEW
1. Product : Improved System
2. Activities : Use post-implementation
review process to monitor and
evaluate.
 Modify the system as needed.
12.22
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ALTERNATIVE SYSTEM-BUILDING APPROACHES
Prototyping
Prototyping
• Process of building experimental system
quickly and inexpensively for demonstration
and evaluation
Prototype
• Preliminary working version of information
system for demonstration and evaluation
Iterative Development
• A process of repeating over and over again
the steps to build system.
12.23
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ALTERNATIVE SYSTEM - BUILDING
APPROACHES
The Prototyping Processes
12.24
Figure 12-7
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ALTERNATIVE SYSTEM-BUILDING APPROACHES
Advantages and Disadvantages of Prototyping
Advantage
• Useful in designing information
system’s end-user interface
Disadvantage
• Rapid prototyping can gloss over
essential steps in systems
development
12.25
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ALTERNATIVE SYSTEM-BUILDING APPROACHES
Application Software Packages
Application software packages
• Set of prewritten, pre-coded application
software programs commercially available
for sale or lease
Customization
• Modification of software package to meet
organization’s unique requirements without
destroying the software’s integrity
12.26
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ALTERNATIVE SYSTEM-BUILDING APPROACHES
Outsourcing
• Practice of contracting
computer center operations,
telecommunications networks,
or applications development to
external vendors
12.27
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APPLICATION DEVELOPMENT FOR THE DIGITAL FIRM
Rapid Application Development (RAD)
• Process for developing systems
in short time period
• Uses prototyping, fourthgeneration tools, and close
teamwork
12.28
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MODULE-3 : UNIT-11
END OF
PLANNING AND
ORGANIZING FOR
INFORMATION
SYSTEMS
DEVELOPMENT
12.29
© 2004 by Prentice Hall