INFORMATION SYSTEM APPLICATIONS

1
INFORMATION SYSTEM APPLICATIONS

• System Development Life Cycle

2
PRIMARY OBJECTIVES

• Explain the phases in the system development life
  cycle
• Identify the guidelines for system development
• Discuss the importance of project management,
  feasibility assessment, information gathering
  techniques and documentation

3
PRIMARY OBJECTIVES (cont.)

• Describe how structured tools such as data flow
  diagrams and entity-relationship diagrams are
  used in analysis and design
• Identify program development as part of the
  system development life cycle

4
WHAT IS THE SYSTEM DEVELOPMENT LIFE CYCLE?

• Organized set of activities used to guide those
  involved through the development of an
  information system

5
Phases in the system development life cycle
(SDLC)

• Planning
• Analysis
• Design
• Implementation
• Support

6
System Life Cycle
System Study
Design
Project definition
Programming
Installation
Evaluate Maintenance
7
Who participates in the system development life
cycle?

• Project team
• Users
• Information systems personnel
• Systems analyst
• Programmers
• Steering committee

8
Project management

• Scope
• Project plan
• Gantt chart

9
Feasibility assessment

• Operational feasibility
• Will the system work in their
  environment?
• Schedule feasibility
• Are project deadlines reasonable?
• Technical feasibility
• Do they have the resources to
  support the system people, hardware,
  software?
• Economic feasibility
• Does it make economic sense?

10
Documentation

• Project notebook - entire collection of
  documentation
• Project dictionary - an automated project
  notebook

11
Data and information gathering techniques

• Reviewing current system documentation
• Observation
• Questionnaires
• Interviews
• Joint-application design (JAD) sessions
• Researching

12
Analysis Phase

• Activities/Tasks
• Fact Gathering
• Data Flow Diagrams (DFD) Used to document the
  flow of information through an information system
  and identify problem areas.

13
Analysis Phase

• Activities/Tasks
• Process Description Used to define the
  internal workings of a process on the DFD.
• Data Dictionary Used to document the data
  definitions and formats.

14
Analysis Phase

• Activities/Tasks
• Data Modeling Designing the necessary
  databases and specifying how they may be
  accessed.
• System Modeling Using requirements to create
  actual plans for the new information system.
• Project Management The process of controlling
  the project to ensure schedules are met,
  estimates are updated, and costs are contained.

15
Detailed Analysis

• Study the current system
• Identify the users wants, needs, and
  requirements
• Present alternative solutions

16
Detailed Analysis

• Structured Analysis and Design Tools
• Data Flow Diagrams
• Structured Analysis (HIPO charts)
• Work Break Down Structure
• Entity Relationship Diagrams
• Decision Tables
• Decision Trees
• Data Dictionary

17
Design phase activities

• Covert DFDs into structure charts (Hierarchical
  diagram of program modules)
• User Interface design (Input/Output)
• Forms
• Data base design
• Structured walkthroughs
• Design Testing Procedures

18
Detailed Design of Software

• Database design
• Data store in DFD
• Logical modeling (ER - diagrams)
• Normalization (Data redundancy integrity)
• Data security
• Program Design
• Program Specification package
• System Flowchart

19
Detailed Design of Software

• CASE tools Computer-aided software engineering
  (CASE)
• Graphics
• Prototyping
• Quality assurance
• Code generators

20
Detailed Design

• Quality review
• Necessary to double-check assumptions and
  design
• Structured walkthrough

21
IMPLEMENTATION PHASE SDLC 4 Develop
programs

• Install and test the new system
• Train and educate users
• Convert to the new system

22
Develop programs

• Program development life cycle (PDLC)
• Analyze
• Design the programs
• Code
• Test the programs
• Maintain the programs

23
Implementation Phase

• Install and test the new system
• System test - verify that all programs work and
  work together
• Integration test - verify that an application
  works with other application in the system
• Acceptance test - performed by users with real
  data
• Types of testing varies

24
IMPLEMENTATION PHASE SDLC 4

• Train and educate users
• Classroom-style lectures
• One-on-one sessions
• User manuals
• CAI

25
IMPLEMENTATION PHASE SDLC 4

• Convert to the new system
• Direct
• Parallel
• Phased
• Pilot conversion

old
New
old
New
Old
New
26
SUPPORT PHASE SDLC 5

• Conduct post-implementation system review
• Identify errors
• Identify enhancements
• Monitor performance

27

• Questions and comments?