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Chapter 6. ~ Information System Development ~. Contents. 2. Guideline to System Development. Participants of System Development Cycle. Phases in System Development Cycle: Planning. Analysis. Design. Implementation. Support. Information System (IS). 3.

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Chapter 6

Chapter 6

~ Information System Development ~


Contents

Contents

2

  • Guideline to System Development.

  • Participants of System Development Cycle.

  • Phases in System Development Cycle:

    • Planning.

    • Analysis.

    • Design.

    • Implementation.

    • Support.


Information system is

Information System (IS)

3

  • It is the hardware, software, data, people, and procedures that work together to produce quality information.

  • System

    • Set of components that interact to achieve common goal.


System development cycle sdc

System Development Cycle (SDC)

4

Phase 2. Analysis

  • Conduct preliminary investigation

  • Perform detailed analysis activities:

    • - Study current system

    • - Determine user requirements

    • - Recommend solution

Phase 1. Planning

Phase 3. Design

  • Review project requests

  • Prioritize project requests

  • Allocate resources

  • Identify project development team

  • Acquire hardware and software, if necessary

  • Develop details of system

Phase 4. Implementation

Phase 5. Support

  • Develop programs, if necessary

  • Install and test new system

  • Train users

  • Convert to new system

  • Conduct post-implementation system review

  • Identify errors and enhancements

  • Monitor system performance


Guideline to system development

Guideline To System Development

5

Arrange tasks into phases (groups of activities).

Involve users (anyone for whom system is being built).

Develop clearly defined standards (procedures company expects employees to follow).


System analyst

System Analyst

6

Responsible for designing and developing information system.

Liaison between users and IT professionals.


Project team

Project Team

7

Formed to work on project from beginning to end.

Consists of users, systems analyst, and other IT professionals.

Project leader is a member of the team who manages and controls project budget and schedule.


Project management

Project Management

8

It is the process of planning, scheduling, and controlling activities during system development cycle.

The goal of project management is to deliver an acceptable system to the user in an agreed-upon time frame, while maintaining cost.


Project management1

Project Management

9

  • Project leader identifies the following elements for the project:

    • Goal, objectives, and expectations of the project, collectively called the scope.

    • Required activities.

    • Time estimate for each activity.

    • Cost estimate for each activity.

    • Order of activities.

    • Activities that can take place at the same time.


Gantt chart

Gantt Chart

10

It is a popular tool used to plan and schedule time relationships among project activities.


Project management software

Project Management Software

11

It is a program (such as Microsoft Office Project 2003) used by project leaders to plan, schedule, and control projects.


Feasibility

Feasibility

12

  • It is the measure of how suitable system development will be to the company.

  • There are four feasibility test:

    • Technical feasibility.

    • Operational feasibility.

    • Economic feasibility (also called cost/benefit feasibility).

    • Schedule feasibility.


Documentation

Documentation

13

Collection and summarization of data and information.

Includes reports, diagrams, programs, and other deliverables.

Project notebook contains all documentation for single project.


Data and information gathering

Data and Information Gathering

14

  • There are six methods:

    • Review documentation.

    • Observe.

    • Questionnaire.

    • Interview.

    • Joint-Application Design (JAD) session.

    • Research.


Why create modify an info system

Why Create/Modify an Info System?

15

To correct problem in existing system.

To improve existing system.

Outside group may mandate change.

Competition can lead to change.


Request for system service

Request for System Service

16

Also known as Project Request, it is the formal request for a new or modified information system.


What is the planning phase

What is the Planning Phase?

17

SDC Phase 1 : Planning

Begins when steering committee receives project request

Steering committee:

decision-making body for the company

Function of committee:

Review and approve project requests

Prioritize project requests

Allocate resources

Form project development team for each approved project


What is the analysis phase

What is the Analysis Phase?

18

SDC Phase 2 : Analysis

Conduct preliminary investigation, also called feasibility study.

Perform detailed analysis.


Preliminary investigation

Preliminary Investigation

19

SDC Phase 2 : Analysis

  • Determine exact nature of problem or improvement and whether it is worth pursuing.

    • Findings are presented in feasibility report, also known as a feasibility study.


Detailed analysis

Detailed Analysis

20

SDC Phase 2 : Analysis

  • It involves three major activities:

    • Study how the current system works.

    • Determine the user’s wants, needs, and requirements.

    • Recommend a solution.

  • Detailed analysis is sometimes known as Logical Design.


Process modeling

Process Modeling

21

SDC Phase 2 : Analysis

  • Sometimes called Structured Analysis and Design, is an analysis and design Technique that describes processes that transform inputs into outputs.

  • Three tools used for process modeling

    • Entity-Relationship Diagram (ERD).

    • Data Flow Diagram (DFD).

    • Project Dictionary.


Entity relationship diagram erd

Entity-Relationship Diagram (ERD)

22

SDC Phase 2 : Analysis

It is a tool that graphically shows connections between entities in system.


Data flow diagram dfd

Data Flow Diagram (DFD)

23

SDC Phase 2 : Analysis

It is a tool that graphically shows flow of data in system.


Project dictionary

Project Dictionary

24

SDC Phase 2 : Analysis

  • Contains all the documentation and deliverables of a project.

  • It helps to keep track of huge amount of details in a system.

  • There are variety of techniques used to enter items in project dictionary:

    • Structured English.

    • Decision Tables.

    • Decision Trees.

    • Data Dictionary.


Structured english

Structured English

25

SDC Phase 2 : Analysis

It is used to explain details of process in project dictionary.


Decision table

Decision Table

26

SDC Phase 2 : Analysis

  • It lists variety of conditions and actions that correspond to each condition.


Decision tree

Decision Tree

27

SDC Phase 2 : Analysis

  • It shows conditions and actions graphically.


Data dictionary

Data Dictionary

28

SDC Phase 2 : Analysis

  • Stores name, description, and other details about each data item.


Object modeling

Object Modeling

29

SDC Phase 2 : Analysis

  • Also known as Object-Oriented Analysis and Design, it combines the data with the processes that act on that data into single unit, called an object.

  • Object:

    • An item that can contain both data and procedures that read or manipulate the data.

  • Uses Unified Modeling Language (UML).

    • UML is a graphical tool for documenting system.


  • Use case diagram

    Use Case Diagram

    30

    SDC Phase 2 : Analysis

    • Graphically shows how actors interact with information system.

  • Actor:

    • User or entity.

  • Use Case:

    • Function that actor can perform.


  • Class diagram

    Class Diagram

    31

    SDC Phase 2 : Analysis

    • Graphically shows classes and subclasses in a system.

    • A Class is group of objects, and can have lower levels called subclasses.


    System proposal

    System Proposal

    32

    SDC Phase 2 : Analysis

    • It assesses the feasibility of each alternative solution.

    • In addition to that, it recommends the most feasible solution for the project.

    • System proposal will be presented to the steering committee, which decides how system will be developed.


    Possible solutions

    Possible Solutions

    33

    SDC Phase 2 : Analysis

    • Buy packaged software, which is a prewritten software available for purchase.

    • Horizontal market software:

      • Meets needs of many companies.

    • Vertical market software:

      • Designed for particular industry.

    • Write own custom software, where the software is developed at user’s request.

    • Outsource: Have outside source develop the software.


    Internet solutions provider

    Internet Solutions Provider

    34

    SDC Phase 2 : Analysis

    • They provide Web hosting services, and these services include:

    • Managing shopping carts.

    • Inventory.

    • Credit card processing.


    Design phase

    Design Phase

    35

    SDC Phase 3 : Design

    • The design phase consists of two major activities:

    • Acquire hardware and software (when necessary).

    • Develop all of the details of the new or modified information system.


    Acquiring necessary h w s w

    Acquiring Necessary H/W & S/W

    36

    SDC Phase 3 : Design

    • To identify all hardware and software requirements of new or modified system.

    • Activities include:

    • Identify technical specification.

    • Solicit vendor proposals.

    • Test and evaluate vendor proposals.

    • Make a decision.


    Detailed design

    Detailed Design

    37

    SDC Phase 3 : Design

    • Also called Physical Design, it is the development of detailed design specifications for components in the proposed solution.

    • Activities include:

    • Database design.

    • Input and output design.

    • Program design.


    Mockup

    Mockup

    38

    SDC Phase 3 : Design

    • It is a sample of input or output that contains the actual data.


    Layout chart

    Layout Chart

    39

    SDC Phase 3 : Design

    • It is the input or output that contains programming-like notations for data items.


    Prototype

    Prototype

    40

    SDC Phase 3 : Design

    • It is a working model of the proposed system.

    • Beginning a prototype too early may lead to problems.

    • A prototype can also be used to gain information from the user.


    Computer aided software engineering case

    Computer Aided Software Engineering (CASE)

    41

    SDC Phase 3 : Design

    • It is a software tool designed to support one or more activities of the system development cycle.

    • It helps to increase the efficiency and productivity of the project development team.


    I case

    I-CASE

    42

    SDC Phase 3 : Design

    • It is an integrated CASE product, also known as a CASE Workbench. It has these capabilities:

    • Project repository:

      • Stores diagrams, specifications, descriptions, programs, and other deliverables.

    • Graphics:

      • Enables drawing of diagrams.

    • Prototyping:

      • Creates models of proposed system.


    I case con t

    I-CASE (con’t)

    43

    SDC Phase 3 : Design

    • Quality assurance:

      • Analyzes deliverables for accuracy.

    • Code generators:

      • Create actual computer programs from design specifications.

    • Housekeeping:

      • Establishes user accounts and provides backup and recovery functions.


    Structured walkthrough

    Structured Walkthrough

    44

    SDC Phase 3 : Design

    • Step-by-step review by project team and users of any system development cycle deliverable.

    • Used to review detailed design specifications before they are given to programming team.

    • Identifies any errors and allows IT personnel to correct them.

    • Used throughout entire system development cycle to review a variety of deliverables.


    Implementation phase

    Implementation Phase

    45

    SDC Phase 4 : Implementation

    • The purpose of this phase is to construct, or build, new or modified system and then deliver it to users.

    • System developers perform four major activities in this phase:

    • Develop programs.

    • Install and test the new system.

    • Train users.

    • Convert to the new system.


    Program development cycle

    Program Development Cycle

    Analyze requirements

    46

    Documentsolution

    Design solution

    Validate design

    Test solution

    Implement design

    SDC Phase 4 : Implementation

    • Programmers write programs from the specifications package created during the analysis process.


    Testing

    Testing

    47

    SDC Phase 4 : Implementation

    • During implementation, there are three types of tests performed by system developers:

    • Unit test:

      • Verifies each individual program works by itself.

    • System test:

      • Verifies all programs in application work together.

    • Integration test:

      • Verifies application works with other applications.

  • Acceptance test :

    • Carried out by the end-user.


  • Train users

    Train Users

    48

    SDC Phase 4 : Implementation

    • Showing users exactly how they will use the new hardware and software in the system.


    Conversion strategies

    Conversion Strategies

    49

    SDC Phase 4 : Implementation

    • It is the process of converting from the old system into the new system.


    Support phase

    Support Phase

    50

    SDC Phase 5 : Support

    • Provides ongoing assistance after system is implemented.

    • This phase consists of four major activities:

    • Conduct a post-implementation system review

      • Meeting to find out if information system is performing according to expectations.

    • Identify errors.

    • Identify enhancements.

    • Monitor system performance.


    Summary

    Summary

    51

    • Guideline to System Development.

    • Participants of System Development Cycle.

    • Phases in System Development Cycle:

      • Planning.

      • Analysis.

      • Design.

      • Implementation.

      • Support.


    Chapter 61

    Chapter 6


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