Chapter 1
CHAPTER 1: INTRODUCTION TO INFORMATION SYSTEMS DEVELOPMENT
1. Computer Based Information Systems
It is an information system that uses computer and communication technology to perform some or all of its tasks.
2. Hardware
- It is the physical components of the computer
- Such as: input devices, one or more processor and main memory, secondary storage devices and output devices
3. Input Device
- Captures and translates data into a form that can be processed and used by other parts of the computer
- Such as keyboards, pointing devices, voice input systems, touch sensitive screens, handwriting recognitions, barcode scanners, image scanners and biometric systems.
4. Output Device
Provide copies of data and information on paper, video screens and others.
5. Software
It is the set of instructions i.e. the computer codes that the hardware devices carry out to process the information. Without software, the computer is absolutely worthless.
6. Database Software
It is a software that allows you to arrange, modify, and extract data from a database to create information.
7. Elements Of Information System
i. Telecommunication & Network – It is vital computer-based tools to help you communicate information to people in other locations.
ii. People- Integral part of an information system provided by the information system.
iii. Procedures – It is a series of steps undertaken in a prescribed manner to accomplish a certain job
8. Phases of Systems Development Life Cycle (SDLC)
Systems Planning (ICPPD) | Initiate Systems Planning Conduct Preliminary Investigation Propose Solutions Prepare a framework for managing the system project development Document Findings |
Systems Analysis (DGADW) | Develop an analysis plan Gather more information Analyze data to determine information needs and system requirements Document existing system Write a systems analysis report |
Systems Design (DPW) | Define requirements for input, output, user interface, database, network, program and control Physically design the new system Write a systems design report |
Systems Construction and Implementation (WTT PC3) | Write out program codes Test and debug program codes Train users Prepare sites Convert sites Convert to new system Conduct a post implementation review |
Systems Maintenance | Perform corrective, adaptive and perfective maintenance |
9. Structured Development Vs Object Oriented Development
Structured Development | Object Oriented Development |
It employs variety of diagrams and documentations standards for describing the requirements of information systems. Disadvantages: 1. Take too long time 2. Require too much documentation | The systems developer first defines the objects needed in the new or revised information systems. |
10. Information Systems Project Team
I. End User
o Directly interact with the information systems
o Supply data to the IS and receive information from the information system
II. Business Analyst
o Analyzes the business aspects and issues surrounding the information system
III. Systems Analyst
o Focuses in information system issues surrounding the system by identifying how information technology can improve business processes
IV. Infrastructure Analyst
o Identifies and implements infrastructure changes on technical issues involved in how the system will interact with the organization’s infrastructure
V. Change Management Analyst
o Focuses on people and management issues surrounding the information systems installation
VI. Project Manager
o Oversees the systems development project from beginning to end, manages the project team, develops and monitors project plan, assigns resources and acts as a primary point of contact for the entire systems project.
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