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System Analysis and Design

1. System Analysis
and Design
Nature of Systems and
System Analysis Concepts

2. Definition of System
•Systems are created to solve
problems.
•One can think of the systems
approach as an organized way of
dealing with a problem.
•In this dynamic world, thus System
Analysis and Design (SAD), mainly
deals with the software development
activities.

3. Definition of System
•A collection of components that work together
to realize some objectives forms a system.
Basically there are three major components in
every system, namely input, processing and
output.




Fig. 1.1: Basic System Components

4. •The objective of the system demands
that some output is produced as a
result of processing the suitable inputs.
•A well-designed system also includes
an additional element referred to as
‘control’ that provides a feedback to
achieve desired objectives of the
system.

5. •In a system the different components are
connected with each other and they are
interdependent. For example, human body .
•It Represents a complete natural system.
• We are also bound by many national systems
such as political system, economic system,
educational system and so forth.

6. Other Examples
•For example, consider an automatic car
wash.
•Tangible inputs for the process are a dirty
car, water, and various cleaning
ingredients.
•Time, energy, skill, and knowledge also
serve as inputs to the system because they
are needed to operate it.

7. •The Processing mechanisms consist of first
selecting which cleaning option you want (wash
only, wash with wax, wash with wax and hand
dry, etc.) and communicating that to the
operator of the car wash.
•A feedback mechanism is your assessment of
how clean the car is.
• Liquid sprayers, shoot clear water, liquid soap, or
car wax depending on where your car is in the
process and which option you selected
Other Examples

8. •The output is a clean car.
•As in all systems, independent elements or
components (the liquid sprayer, foaming
brush, and air dryer) interact to create a
clean car.
Other Examples

9. Elements of System
•In most cases, systems analysts operate in
a dynamic environment where change is a
way of life. The environment may be a
business firm, a business application, or a
computer system. To reconstruct a system,
the following key elements must be
considered:

10. Elements of System
1.Outputs and inputs.
2.Processor(s).
3.Control.
4.Feedback.
5.Environment.
6.Boundaries and interface

11. Elements of System
1.Outputs and inputs
•Inputs are the elements (material,
human resources, and
information) that enter the
system for processing. Output is
the outcome of processing.

12. 2. Processor(s)
•Involves the actual transformation of
input into output. It is the
operational component of a system.
Processors may modify the input
totally or partially, depending on the
specifications of the output.
Elements of System

13. 3. Controls
•In a computer system, the operating
system and accompanying software
influence the behavior of the system.
Output specifications determine what
and how much input is needed to
keep the system in balance.
Elements of System

14. 4. Feedback
•Feedback may be positive or negative,
routing or informational.
•Positive feedback reinforces the
performance of the system. It is routine
in nature.
•Negative feedback generally provides the
controller with information for action.
• In systems analysis, feedback is
important in different ways.
Elements of System

15. 5.Environment
•The environment is the “suprasystem” within
which an organization operates.
•It is the source of external elements that
impinge on the system. In fact, it often
determines how a system must function.
•For example, the organization’s environment,
consisting of vendors, competitors,
and others, may provide constraints
and, consequently, influence the actual
performance of the business.
Elements of System

16. 6.Boundaries and Interface
•A system should be defined by its
boundaries – the limits that
identify its components, processes
and interrelationship when it
interfaces with another system.
Elements of System

17. Types of System
1.Physical or abstract systems.
2.Open or closed systems.
3.'Man-made' information
systems.
4.Formal information systems
5.Informal information systems

18. Types of System
1.Physical System
•Physical systems are tangible entities
that may be static or dynamic in
operation.
•For example, the physical parts of the
computer center are the officers,
desks, and chairs that facilitate
operation of the computer.

19. Types of System
2. Open or Closed System
Open System
•It permits interaction across its
boundary; it receives inputs from and
delivers outputs to the outside.
•An information system falls into this
category, since it must adapt to the
changing demands of the user.

20. Types of System
2. Open or Closed System
Close System
•In contrast, a closed system is
isolated from environmental
influences.

21. Types of System
3. Man Made System
•An information system is the basis for
interaction between the user and the
analyst. It provides instruction,
commands and feedback. It
determines the nature of the
relationships among decision-makers.
In fact, it may be viewed as a decision
center for personnel at all levels.

22. Types of System
4. Formal Information System
-Organizational Representation

5.Informal Information System
- Employee based system

23. •Information System, Plays vital role
in the business and operations,
enterprise collaboration and
management, and strategic success
of business that must operate in an
internetworked global
environment.

Business System
/ Information System

24. Analysis - Definition
•Analysis is the process of
breaking a complex topic or
substance into smaller parts to
gain a better understanding of
it.

25. Analysis
•Characteristics
The purpose of analysis in the planned change
process is to facilitate decision-making.

Analysis clarifies the nature and dynamics of
the change opportunity and the relevance of
possible responses.

However, it is not realistic to expect analysis to
provide “the answer”

26. System Analysis
•It is the process of collecting
factual data, understand the
processes involved, identifying
problems and recommending
feasible suggestions for
improving the system
functioning.

27. System Analysis
•It attempts to give birth to a new efficient
system that satisfies the current needs of
the user
•The result of this process is a logical
system design.
•Systems analysis is an iterative process
that continues until a preferred and
acceptable solution emerges

28. Purpose of System Analysis
•Studying the business processes
• Gathering operational data
• Understand the information flow
• Finding out bottlenecks and evolving
solutions
• Overcoming the weaknesses of the
system so as to achieve the
organizational goals.

29. Objectives of System Analysis
To Find answers in the business process:
•What is being done?
• How is it being done?
•Who is doing it? When is he doing it?
• Why is it being done?
•How can it be improved
• It is more of a thinking process and involves the
creative skills of the System Analyst.

30. Qualities of a System Analyst
1. The system analyst must be able to
communicate in writing and orally.
2. The analyst must easily get along with
people.
3. The analyst must be a good listener
and be able to react to what people
say.

31. Qualities of a System Analyst
4. The analyst must be knowledgeable of
technology, a decent general
knowledge of concepts and terms are
essential.
5. The analyst must be knowledgeable of
business. The analyst is not expected
to be an expert in business but a
decent understanding of the client's
world is required.

32. Responsibilities of
a System Analyst
•Developing cost analysis
•Design considerations
•Staff impact amelioration
•Implementation time-lines

33. Scientific Method
of Solving Problem
1. Define a problem or opportunity in
a systems context.
2. Gather data describing the problem
or opportunity.
3. Identify alternative solutions.
4. Evaluate each alternative solution.

34. Scientific Method
of Solving Problem
5. Select the best solution.
6. Implement the selected
solution.
7. Evaluate the success of the
implemented solution.