Introduction to System Analysis and Design
IT 223
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Introduction to System Analysis and Design
Information technology (IT) is a
combination of hardware, software,
and telecommunications systems that
support business operations, improve
productivity, and help managers
make decisions.
A key part of IT involves system
analysis and design which is the
process of developing information
systems that effectively use hardware,
software, data, processes and people
to support the company’s business
objectives.
IT 223
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Introduction to System Analysis and Design
Business Process Modeling
Business profile defines a
company’s overall functions,
processes, organization,
products, services, customers,
suppliers, competitors,
constraints, and future
direction.
Business model graphically
represents business functions
that consists of business
processes.
IT 223
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Introduction to System Analysis and Design
Business Process Modeling
Business process describes
specific events, tasks, and
desired results.
IT 223
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Introduction to System Analysis and Design
Information System
Components
A system is a set of related
components that produces
specific results.
In an information system, data
consists of basic facts that are
the system’s raw material.
Information is data that has
been changed into a useful form
of output.
The task of changing data into
information is called processing.
IT 223
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Introduction to System Analysis and Design
Information System Components
An information system has five
key components: hardware,
software, data, processes, and
people.
Processes
IT 223
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Introduction to System Analysis and Design
Hardware
Hardware refers to the physical
layer of the information system.
Software
Software consists of system
software and application software.
 System software controls the
computer and includes the
operating system, device drivers
that communicate with
hardware, and utilities that
handles tasks
 Application software consists of
programs that support users and
enable companies to carry out
business functions.
IT 223
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Introduction to System Analysis and Design
Data
An information
system
transforms data
into useful
information.
Processes
Also known as procedures describe
the tasks that users, managers, and
IT staff members perform.
People
Users, sometimes called end users,
include employees, customers,
vendors, and others who interact
with an information system.
 Internal
 External
IT 223
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Introduction to System Analysis and Design
Categories of Companies
Production-oriented companies
primarily manufacture and sell
products.
e.g. Motorola, Intel and Compaq
Service-oriented companies
primarily offer information or
services, or sell goods produced by
others.
e.g. AT&T, United Airlines & Wal- Mart
Internet-dependent firm often
described as a dot-com company
e.g. Amazon.com and e-trade.com
Brick-and-mortar
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Introduction to System Analysis and Design
Characteristics of information systems
1. Does this system interact with other
systems? Purchasing
Production
System
System
Finance
System
Electronic Data Interchange (EDI) –
the process that involves computer-to
computer transfer of data between
companies
2. What are the system’s boundaries?
System boundary indicates where
one system ends and another system
begins.
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Introduction to System Analysis and Design
Characteristics of information systems
3. Will the system handle specialized
business needs?
4.What size is the company, and what
growth is forecast?
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Introduction to System Analysis and Design
Types of Business Information System
Enterprise Computing Systems
refers to information systems that
support company wide data management
requirements
e.g. Airline reservation, credit card billing
Transaction Processing Systems (TP)
TP systems and online transaction
processing (OLTP) systems are called
operational systems because they process
data generated by day-to-day business
operations
e.g. Customer billing, accounts receivable
Business Support Systems (BSS)
provide job-related information support
to users at all levels of a company
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Introduction to System Analysis and Design
Knowledge Management Systems
sometimes called expert systems because
they simulate human reasoning by
combining a knowledge base and
inference rules that determine how the
knowledge is applied
User Productivity Systems
provide employees at all organizational
levels with a wide array of tools that can
improve quality and job performance
Information Systems Integration
Systems that combine enterprise
computing, transaction processing,
business support, knowledge
management, and user productivity
features
IT 223
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Introduction to System Analysis and Design
Tools and Techniques
Modelling produces a graphical
representation of a concept or
process that systems developers can
analyse, test, and modify.
•Business model describes
business functions
•Data model describes data
structures and design
•Object model describes objects,
which combine data and
processes
•Network model portrays the design
and protocols of
telecommunications links
•Process model describes system logic
and processes that programmers
use to develop code modules
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Introduction to System Analysis and Design
Tools and Techniques
Prototyping involves the creation of
an early working version of the
information system or its components.
Computer-Aided Systems Engineering
(CASE) is a technique that uses
powerful programs, called CASE tools,
to help systems analysts develop and
maintain information systems.
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Introduction to System Analysis and Design
Tools and Techniques
Joint Application Development and
Rapid Application Development
Both approaches use teams composed
of users, managers, and IT staff to
complete projects. JAD involves teambased fact- finding techniques, while
RAD is more like a condensed version
of the entire development process.
Other tools
Microsoft VISIO use by SA to draw
flowcharts, data flow diagrams,
entity-relationship diagrams, network
diagrams and business process
diagrams
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Introduction to System Analysis and Design
Methodologies
Structured Analysis uses a series of
phases, called the systems development
life cycle (SDLC) to plan, analyse,
design, implement, and support an
information system.
Object-Oriented Analysis (0-0) analysis
combines data and the processes that
act on the data into things called objects.
An object is member of a class, which is a
collection of similar objects. Objects possess
characteristics called properties, which it
inherits from its class or possesses on its
own. A built-in processes called methods
can change an object’s properties. One
object can send information to another
object by using a message.
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Introduction to System Analysis and Design
Methodologies
PERSON
Name
Address
SSS number
INSTRUCTOR
Name
Address
SSS number
Office location
Office phone
Date hired
Inherited
Properties
Other
Properties
STUDENT
Name
Address
SSS number
major]
GPA
Adviser
The PERSON class includes INSTRUCTOR and STUDENT
objects, both have inherited properties and other properties
Other Development Strategies
Microsoft has developed an approach
called Microsoft Solutions Framework
(MSF) that documents the experience of
its own IT teams.
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Introduction to System Analysis and Design
Systems Development Life Cycle
Structured analysis uses a technique
called the systems development life
cycle (SDLC) to plan and manage the
systems development process.
The SDLC Model includes the
following steps:
1.
2.
3.
4.
5.
Systems planning
Systems analysis
Systems design
Systems implementation
Systems operation and support
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Introduction to System Analysis and Design
System Development Life Cycle
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Introduction to System Analysis and Design
System Development Life Cycle
Planning
Analysis
Design
Operation
and
Support
Implementation
An alternative model of the SDLC that shows the
interaction of planning, analysis and design,
which leads to implementation and then to
operation and support.
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Introduction to System Analysis and Design
System Development Guidelines
1. Stick to an overall development
plan.
2. Ensure that users are involved in
the development process.
3. Identify major milestones for
project review and assessment.
4. Establish interim checkpoints
between major milestones to
ensure that the project remains
on schedule.
5. Be flexible within the framework
of your plan.
6. Provide accurate and reliable
cost and benefit information.
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Introduction to System Analysis and Design
Information Technology Department
The information technology (IT)
department develops and maintains a
company’s information systems.
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Introduction to System Analysis and Design
Role of Systems Analyst
• investigates
• analyses
• designs
• develops
• installs
• evaluates
• and maintains a company's
information systems.
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