Ict2621 SUMMARISED
NOTES 2022/2023
, CHAPTER 01: INTRODUCTION
IT: Combination of hardware, software and services that people use to manage, communicate and
share information.
SYSTEMS ANALYSIS AND DESIGN: Step-by-step process for developing high-quality IT systems.
INFORMATION SYSTEM: Combines technology, people and data to provide support for business
functions.
SYSTEMS ANALYST: Valued member of IT department who helps plan, develop and maintain
information systems.
SYSTEM: Set of related components that produces specific results.
MISSON-CRITICAL SYSTEM: A system that is vital to a company’s operations.
DATA: Basic facts that are the system’s raw material.
INFORMATION: Data that has been transformed into output that is valuable to users.
---INFORMATION SYSTEM COMPONENTS---
1. Hardware
HARDWARE: Everything in the physical layer of the IT system.
SERVER FARM: Large concentration of servers working together.
MOORE’s LAW: Number of transistors on an integrated chip will double about every 24
months.
2. Software
SOFTWARE: Programs that control the hardware and produce desired information or results.
SYSTEM SOFTWARE: Manages hardware components.
APPLICATION SOFTWARE: Programs that support day-to-day business functions and provide
users with the information that they need.
ENTERPRISE APPLICATIONS: Company-wide applications.
HORIZONTAL SYSTEM: Can be adapted for use in many different companies.
VERTICAL SYSTEM: Designed to meet the unique requirements of a specific business of
industry.
LEGACY SYSTEMS: Older systems.
3. Data
4. Processes
, PROCESSES: The tasks and business functions that users, managers and IT staff perform to
achieve specific results.
5. People
STAKEHOLDERS: People who have an interest in information systems.
USERS: People who interact with the system.
---BUSINESS MODELS---
1. Internet Model
ECOMMERCE: Internet-based commerce.
APP: Small application that the user can interact with.
2. B2C
B2C: Business-to-consumer
3. B2B
B2B: Business-to-business.
EDI (Electronic data interchange): A data sharing arrangement between two companies that
enabled computer-to-computer data transfer, usually over private telecommunications lines.
SUPPLY CHAIN: Refers to all companies who provide materials, services and functions
needed to provide a product to a customer.
BUSINESS PROFILE: Overview of company’s mission, functions, organization, products, services,
customers, suppliers, competitors, constraints and future direction.
BUSINESS PROCESS: Specific set of transactions, events and results that can be described and
documented.
BPM (Business Process Model): Graphical display of one or more business processes.
BPMN (Business Process Modelling Notation): Standard shapes and symbols used to represent
events, processes, workflows etc.
ENTERPRISE COMPUTING: Information systems that support company-wide operations and data
management.
ERP (Enterprise Resource Planning): Provide cost-effective support for users and managers
throughout companies.
TP (Transaction Processing) systems: Process data generated by day-to-day business operations.
BUSINESS SUPPORT SYSTEMS: Provide job-related information support to users at all levels of a
company.
MIS (Management Information Systems): Business support systems for managers.
RFID (Radio Frequency Identification): Data acquisition technology, which uses high frequency radio
waves to track physical objects.
, KNOWLEDGE BASE: Large database that allows users to find information by entering keywords or
questions in normal English phrases.
INFERENCE RULES: Logical rules that identify data patterns and relationships.
USER PRODUCTIVITY SYSTEMS: Technology that improves productivity, such as email, voice mail,
video and web conferencing and word processing programs.
GROUPWARE: Programs that allow users to share data and collaborate on projects.
STRATEGIC PLANS: Long-range plans which define a company’s overall mission and goals.
MODELLING: Produces a graphical representation of a concept or process that systems developers
can analyse, test and modify.
BUSINESS MODEL: Describes information that a system must provide.
PROTOTYPE: An early working version of an information system.
CASE (Computer-aided systems engineering): A technique that uses powerful software, called a
CASE tool, to help systems analysts develop and maintain information systems. Many CASE tools can
generate program code.
---SYSTEMS DEVELOPMENT METHODS---
1. STRUCTURED ANALYSIS:
SDLC (Systems development life cycle): A series of phases, to plan, analyze, design, implement
and support an information system.
BUSINESS RULES:
DFD (Data flow diagram): A model which uses various symbols and shapes to represent data
flow.
WATERFALL MODEL:
DELIVERABLE: The result of each phase of the SDLC.
---SDLC PHASES--- (PADIS)
1. Systems Planning
SYSTEMS REQUEST: A request to the IT department, which describes problems or
desired changes in an information system or a business process.
PRELIMINARY INVESTIGATION: The evaluation of an IT related business opportunity or
problem.
FEASIBILITY STUDY: A study that reviews anticipated costs and benefits, and
recommends a course of action based on operational, technical, economic and time
factors.
2. Systems Analysis
REQUIREMENTS MODELLING: The analyst investigates business processes and
documents what the new system must do to satisfy users.
SYSTEM REQUIREMENTS DOCUMENT: The deliverable for this phase, which describes
management and user requirements, costs and benefits and outlines alternative
development strategies.
