DS-SAD presentation notes presentation notes presentation notes.ppt

ds sad notes

1. STRUCTURED SYSTEM
ANALYSIS & DESIGN

2. The Concept of System
A System is a group of integrated
parts, which have the common
purpose of achieving some
objective(s).
A system is an orderly grouping of
interdependent components linked
together according to a plan to
achieve a specific goal.

3. Characteristics of a System
•A system has more than one element.
•All the elements of a system are
logically/physically related.
•All the elements of a system are controlled in a
manner to achieve the system goal.
•It is observed that following characteristics are
present in all systems such as Organisation,
Interaction, Interdependence, Sub-systems,
Integration and Central Objective.

4. INPUT
PROCESS
OUTPUT
The essential elements of of inputs are Accuracy, Timeliness,
Proper format,economy.
Process involves the programs and the way in which data is
processed. The processing involves a set of logical steps.
We must determine what the objectives or goals are, what do we
intend to achieve; in other words, what is the main aim behind the
system.
ELEMENTS OF A SYSTEM

5. In addition to the above
components, other components
play an important role. These are
Control, feedback, Environment,
Boundaries and interface.

6. Types of Systems
1. Physical Systemsare tangible
entities that may be static or dynamic
in operation.
2. Abstract Systemsare conceptual or
non-physical entities. Such systems
just involve abstract conceptualization
of physical situations. Example : A
model of an Aircraft.

7. 3. An Open Systemcontinually interacts
with its environments. It receives inputs
from and delivers outputs to the outside.
Example : Information System, Business
System, Human Body System
4. A Closed System is isolated from
environmental influences. In reality
completely closed systems are very
rare.

8. 5. A Deterministic system is one
in which the occurrence of all
events is perfectly predictable.
6. A Probabilistic system is one
in which the occurrence of
events cannot be perfectly
predicted.

9. Different types of Information Systems(CBIS)
1. Transaction Processing Systems :A transaction
is any event or activity that affects the whole
organisation. A TPS can be defined as a computer
based system that captures, classifies, stores,
maintains, updates and retrieves transaction data
for record keeping and for input to other type of
CBIS.
2. Management Information System :It can be
described as information system that can provide
all levels of management with information essential
to the running of smooth business.

10. 3.Decision Support Systems:It assist managers
who must make decisions that are not highly
structured, often called unstructured or semi-
structured decisions. Judgment of the manager
plays a vital role in decision making where the
problem is not structured. The DSS supports, but
does not replace, judgement of managers.
4.Office Automation Systems:It is a multi-
function, integrated CBIS, that allows many
office activites to be performed in an electronic
mode. Such as word-processing, email etc.

11. TOP MANAGEMENT(DSS)
MIDDLEMANAGEMENT (MIS)
FIRST LINE MANAGEMENT (TPS)
CLERICAL PERSONEL(OAS)
FIGURE : THE
HIERARCHICAL
VIEW OF CBIS

12. Real-Time System :It must satisfy the requirement
of producing the desired result before a certain
deadline. If it delivers the correct result, but after the
deadline, the system is regarded as having failed.
Example : Satellite Launching, Airplane Control,
Automated Factory.
Distributed Computing System :It consists of a
collection of nearly autonomous processors or PCs
that inter communicate to achieve a computing
system. Each processor possesses a private memory
and communicates with the rest through an
interconnected network. Example : RRS

13. A distributed database system consists of a
collection of sites, each of which maintains a
local database system. Each site is able to
process local transactions, those transactions
that access data only in that single site. In
addition, a site may participate in the
execution of global transactions, those
transactions that access data in several sites.
The execution of global transactions requires
communication among the sites.

14. Approach to System Development
1. Structured System Analysis & Design
2. Prototype Model
3. Joint Application Development Model
4. RAD Model

15. SSAD has 3 phases
1. Feasibility Study
2. System Analysis
3. System Design

16. Prototype is a working model
which is based on interaction
between analysts and users, built
as a preliminary solution to a
problem.
JAD is a structured process in
which users, managers and the
system analysts work together in
the design and development of
an application.

17. Types of System Model
1. Schematic Model : It is a 2 dimensional
chart depicting system elements and their
linkages.
2. Flow System Model : It depicts the orderly
flow of logic. The focus of this model is to
show the inter-relationships and flowsthat
hold various components of a system.

18. Static system model uses Gantt
chart using bars which show each
activity in a system’s project and
the amount of time the activity will
take.
Dynamic System model depicts an
ongoing, constantly changing
system such as business systems.

19. CHAPTER –2
ROLE OF A SYSTEMS ANALYST
•Who is Systems Analyst ? A systems analyst is
a person who conducts a study, identifies
activities and objectives and determines a
procedure to achieve the objectives. Designing
and implementing systems to suit organizational
needs are the functions of the systems analyst.
The analyst is a person with unique skills. He
plays a major role in seeing business from
computer technology.

20. What a Systems Analyst does?
1. The first & perhaps the most difficult task of
systems analyst is problem definition.
2. He uses various methods for data gathering to get
the correct solution of a problem.
3. Having gathered the data relating to a problem, he
analyses them and thinks of plan to solve it.
4. He coordinate the process of developing solutions.
5. Systems must be thoroughly tested. The systems
analyst often coordinates the testing procedures and
helps in deciding whether or not the new system is
meeting standards established in the planning phase.

21. Attributes of an Systems Analyst
1. Knowledge of people
2. Knowledge of Business functions
3. Knowledge of Data processing principles
4. Ability to communicate
5. Flexibility
6. An analytical mind
7. Well educated with sharp mind