Introduction to Management Information Systems
Chapter 6 System Development
HTM 304
Spring 06
What Systems to be developed
Many different types of systems in the organization
Operations
Integrated Systems
(e.g. ERP, etc)
EAI
IT Infrastructure
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Inter –Organizational
Internet
Information
Systems
Other
(B2B, SRM, etc.)
organizations
System Development Fundamentals
System Development – a process for creating and
maintaining information systems (IS)
-- Also called System Analysis and Design (Dr. Fang &
Kumar, Summer 2007)
Developing an IS involves all 5 components:
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Personnel Involved
Constant interaction between Users (MIS,
HTM 304) and IT professionals (System
Analysis & Design, HTM 425)
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Video – System Development
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Think Big About System Development
Many students are new to the systems
development process due to working
with personal computer tools.
The scope of work is large with largescale corporate information systems
and may be global with different
languages and cultures.
Management of resources is a critical
success factor.
Comprehensive processes are
required for project staff to follow and
adhere to in order to successfully meet
project and systems objectives.
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Think Big (cont)
Three software sources
Off-the-shelf
Off-the shelf-with adaptation
Tailor-made
Major IS rarely off-the-shelf
due to involvement of
company people
and resources
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System Development Is Challenging
Systems development
difficult and risky
Many projects never finished
Some projects finish
200-300% over budget
Some projects finish on
schedule and within budget
but don’t meet the goals
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System Development Challenges
Difficulties in determining requirements
Changes in requirements
Scheduling and budgeting difficulties
Changing technology
Diseconomies of scale
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Systems Development Methodologies
There are many different system
development processes
System Development Life Cycle (SDLC)
Rapid Application Development (RAD)
Object-oriented System Development (OOD)
Extreme Programming (XP)
Information Systems Differ
No single process works for all situations
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Scales of Information Systems
System Type
Personal
Supports one person with limited set
of requirements
Workgroup
Supports group of people normally
with a single application
Enterprise
Supports many workgroups with many different
applications
Interenterprise
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Description
Supports many different organizations with many
different cultures, countries and heritages
The 5-Phase Version of SDLC in our book
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System Definition Phase Tasks
Define project
Goals and objectives
Scope – statement of work
Assess feasibility
Cost (budget)
Schedule
Technical
Organizational feasibility
Form a project team
Project manager
In-house IT staff
Outside consultants and staff (as needed)
User representatives (management and staff)
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SDLC Requirement Analysis Phase
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Requirement Analysis Phase Tasks
The most important phase in the system development
process is determining system requirements.
If the requirements are wrong, the system will be wrong.
If the requirements are determined completely and correctly,
then the design and implementation will be easier and more
likely to result in success.
Seasoned and experienced system analysts know
how to conduct interviews to bring such
requirements to light.
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Obtain User Approval Before You Move-on
Once the requirements have been specified, the users must
review and approve them before the project continues.
The easiest and cheapest time to alter the information system
is in the requirements phase.
Changing a requirement in the implementation phase may
require weeks of reworking applications components and the
database.
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Component Design Phase
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Component Design Phase
Each of the five components is designed in this stage.
The team designs each of the five components by
developing a list of alternatives.
Each alternative is evaluated against the requirements.
Typically the best alternative that meets the
requirements is selected.
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Hardware Design
Team determines specifications
for hardware they want to
acquire
Team NOT designing hardware
Typically, large company has
some type of computer network
infrastructure
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Hardware Networking Alternatives
PC or LANs over public
Internet
Point-to-point leased lines
Lease time on some type of
PSDN
Create Virtual Private
Network (VPN) over
Internet
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Program Design
Depends on program source
Off-the-shelf – team
must assess products
and evaluate them
against requirements
Off-the-shelf with alteration
- team IDs products and
assesses alterations
Custom-design programs –
team write specifications
(documentation) for program code
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Database and Procedure Design
Database design
Convert database design to data model
If off-the-shelf DB, little design needed
Procedure design
Procedures must be developed for system users and operations
personnel to follow
Procedures typically address
Normal processing: procedures for using the system to accomplish
business tasks
Backup: user procedures for backing up data and other resources
Failure recovery: Procedure to continue operation when system fails
and procedures to convert back to the system after recovery
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People Component -- Design of Job Descriptions
Job descriptions needed for both users
and operations personnel
New IS may require new jobs
Organizations may have to add new
duties and responsibilities due to
information systems changes and
enhancements
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Implementation Phase
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Comparison of Design and Implementation
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System Conversion
4 ways to implement system conversion
Pilot – Implement entire system on limited
portion of the business
Phased- New system installed in pieces
across organization
Parallel – New system runs in parallel with
old system for a while
Plunge – Old system turned off and new
system turned on immediately
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Maintenance Phase
New needs
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Information System Maintenance
Either fixing system to make it do
what is expected
Or adapting system to changing requirement
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Problems with SDLC
The most formal procedure to develop large IS project
Systems development seldom smooth
Sometimes need to crawl back up waterfall
Difficulty documenting requirements in usable way
Scheduling and budgeting difficult, especially for large projects
with large SDLC phases
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Review of SDLC
What are the five phases?
Which phase is the most important?
Briefly describe the five phases.
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Other Developing Methods
Rapid application development (RAD)
Object-oriented systems development (OOD)
Extreme programming (XP)
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RAD
Basic idea - break up design
and implementation phases
of SDLC into smaller pieces
Use iterative process – build
a piece of the system, test it
and then make it better
Get user input with every iteration
- You are always involved.
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RAD – Extensive Use of Prototypes
Extensive use of prototypes
A mock-up of aspect of new system and could be:
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-- Form
-- Report
-- Database Query
--User Interfaces
E-R modeling of the Data Form
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CASE Tools
CASE: Computer-assisted systems engineering
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Summary of RAD Characteristics
Design / implement / fix development process
Continuous user involvement throughout
Extensive use of prototypes
Joint Application Design (JAD)
Use of CASE Tools
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Object-Oriented Systems Development (OOD)
Began after RAD – mid 1990s
Driven by new program development method – Object-Oriented
Programming (OOP)
A series of diagramming techniques called Unified Modeling Language
(UML) facilitates OOP development.
Example:
Unified Process
(UP)
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Extreme Programming
Emerging Technique Developing Computer Programs
Not useful for large scale development system requiring business
processes & procedures (or at least not yet realized)
There are cases where organizations have used it successfully in
developing application programs.
Three main characteristics
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1)
Customer-Centric
2)
Just-In-Time (JIT) Design
3)
Paired Programming
Compare Development Techniques
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