System Analysis and Design
Introduction to System Analysis
and Design
- Dr. Mahmoud Abu-Arra
- Mr. Ahmad Al-Ghoul
Learning Objectives
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Describe the systems development
life cycle
Discuss Systems Development
Guidelines
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Introduction
 Systems development life cycle (SDLC) is a common
methodology for system development in many
organizations; it features several phases that mark the
progress of the systems analysis and design effort
 Every text book and information systems development
organization uses a slightly different life cycle model
 SDLC involves a series of phases.
 You can think about SDLC like constructing a building.
First, you would list specific objectives for the project.
Then you might hire an architect to present an overall
concept and create a set of drawings to show how the
building will fulfill your objectives. Later, you would need
detailed blueprints for the workers. When the building is
done, you would check it out, test everything, turn it
over to the new occupants, and make sure they are
satisfy with the results.
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The Systems Development Life
Cycle
An idea
Planning and
Analysis
Design and
Implementation
operation, security
and support
Time
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The Systems Development Life
Cycle
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SDLC is Series of steps used to manage the
phases of development for an information system
SDLC used to plan and manage the systems development
process
The life cycle can be thought as a circular process in
which the end of the useful life of one system leads to the
beginning of anther project that will develop a new
version or replace an existing system altogether
SDLC is not necessary to be sequentially ordered set of
phases, the specific steps and their sequence are meant
to be adapted as required for a project
In a SDLC you can complete some activates in one phase
in parallel with some activates of anther phase
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The Systems Development Life
Cycle
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In some cases the SDLC is iterative; that is,
phases are repeated as required until an
acceptable system is found
The SDLC used in an organization is an orderly
set of activates conducted and planned for each
development project
Each activity or phase in the SDLC has specific
outcomes that feed important information to
other phases
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Introduction to SAD
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The Systems Development Life
Cycle
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Each of the phases include a set of steps, which
rely on techniques that produce specific
document files that provide understanding about
the project.
Individual companies use customized life
cycles
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The Systems Development Life
Cycle
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Traditionally pictured as
a waterfall model
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In waterfall model the
result of each phase,
which is called end
product, flaws
sequentially into the next
phase
The adjacent phases
interact, as shown by
dotted lines
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Introduction to SAD
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The Systems Development Life
Cycle
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Alternative model
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In the alternative model
of the SDLC, planning,
analysis, and design
interact continuously,
followed by
implementation and
operation and support
interactive model
depicting real world
practice and the constant
dialog among users,
managers, and systems
developers
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The Systems Development Life
Cycle
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System development life cycle
Planning
includes the following steps:
 Systems planning
Analysis
Systems Operation
and Support
 Systems analysis
 Systems design
Implementation Design
 Systems implementation
 Systems operation, support,
and security
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Introduction to SAD
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The Systems Development Life
Cycle
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Systems planning
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Purpose is to identify the nature and scope of the
business opportunity or problem
Systems request – begins the process & describes
problems or desired changes in an information system
or business process
Systems planning includes preliminary investigation
to identify the nature and scope of the business
opportunity or problem. The outcome of preliminary
investigation will affect the entire development
process. A key part of the preliminary investigation is
a feasibility study that reviews costs and benefits and
recommends a course of action based on operational,
technical, economic and time factors.
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The Systems Development Life
Cycle
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Systems Analysis
Purpose is to build a logical model of the new system
The analysis phase answers the questions of who will use the
system, what the system will do, and where and when it will be
used.
During this phase the project team investigates any current
systems, identifies improvement opportunities, and develops a
concept for the new system.
 First step is requirements modeling, where you investigate
business processes and document what the new system must
do. To understand the system, you perform fact-finding using
techniques such as interviews, surveys, document review,
observation, and sampling
 End product is the System requirements document which
describes management and user requirements, costs, and
benefits, and outline alternative development strategies.
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The Systems Development Life Cycle
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Systems Design
In this phase the designer decided how the system will operate, in
terms of the hardware, software, and network infrastructure; the
user interface, forms, and reports that will be used; and the specific
programs, databases, and files that will be needed.
 Purpose is to create a blueprint that will satisfy all documented
requirements
 Identify all outputs, inputs, and processes
 Avoid misunderstanding through manager and user involvement
 End product is system design specification
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Logical Design
 Concentrates on business aspects of the system
Physical Design
 Technical specifications
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The Systems Development Life
Cycle
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Systems Implementation
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New system is constructed
Write, test, & document programs
File conversion occurs
Users, managers, IT staff trained to operate
and support the system
System evaluation performed, to determine
whether the system operates properly and if
costs and benefits are within expectations.
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The Systems Development Life
Cycle
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Systems Operation, Support, and security
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New system supports operations
Maintenance changes correct errors or meet requirements
Enhancements increase system capability by provide new
features and benefits
The objective during this phase is to maximize return on the IT
investment
Security controls safeguard the system from both external and
internal threats
A well-designed system will be secure, reliable, maintainable,
and scalable so it can expand to meet new business
requirements and volumes
After several years of operation, systems need extensive
changes
SDLC ends with system replacement
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Systems Development Guidelines
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With experience as a system analyst, you will develop
your own style and techniques. Although each project is
different and have its constraints, rules, so you can
decide which methods and technique you will use, you
should consider some basic guidelines as you build an
information system.
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Planning:
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Involve users throughout the development process
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Ensure that users are involved in the development process,
especially when identifying and modeling system requirements
Listening is Very Important
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stick to an overall development plan
The best system is the one that meets user needs most effectively.
When you interact with users, you must put aside any preconceived
notations and listen closely
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Systems Development Guidelines
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Create a Time Table with Major Milestones
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Identify Interim Checkpoints
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System development is a dynamic process, and overlap often
exists between the phases of system planning, analysis,
design, and implementation
Develop Accurate Cost and Benefit Information
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Establish interim checkpoints between major milestones to
ensure that the project remains on schedule
Remain Flexible
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Identify major milestones for project review and assessment.
At those milestones, managers and systems developers must
decide whether to proceed with the project, redo certain
tasks, return to earlier phase, or terminate the project
Provide accurate and reliable cost estimation and benefit
information to managers at start of each phase
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Sequence Summary
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In this Sequence we have
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Described the systems development life cycle
Distinguished between Traditional SDLC as a
waterfall model and the Alternative SDLC
model
Defined system planning, system analysis,
system design, system implementation,
System Operation, Support, and security
Discussed systems development guidelines
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Reference
[1] System Analysis and Design, Sixth Edition
Authors: Gary B. Shelly, Thomas J. Cashman and Harry J. Rosenblatt ,
Publisher: SHELLY CASHMAN SEWIES.
[2] Modern Systems Analysis and Design Third Edition
Authors: Jeffrey A. Hoffer , Joey F. George, Joseph S. Valacich
Publisher: prentice hall
[3] System Analysis and Design, 3rd Edition
Authors: Dennis, Wixom, & Roth
Publisher: John Wiley & sons
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System Analysis and Design
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