Structured System Analysis and Design: UNIT-I Notes, What is System, Organization, System Analysis, System Development Life Cycle

1. Structured System Analysis and
Design

2. SSAD
• It is widely used in the computer-application
development method.
• The SSAD divides the application development
projects into modules, steps and tasks.
• Objectives
– Improve in project management & control
– Develop better quality systems
– Make a project resilient to the loss of the staff

3. What is System
• A ‘system’ which means an organized relationship
among functional unit or components.
• A System is exists because it is designed to achieve
one or more objectives.
• A System is an orderly arrangement of its
components.
• The components of a system have structure and
order

5. System & its parts
• A system has nine Characteristics
– Components
– Interrelated Components
– A Boundary
– A Purpose
– An Environment
– Interfaces
– Input
– Output
– Constraints

7. • Component: A System is made up of
components. It is either irreducible part or
aggregate of parts, and also known as
‘Subsystem’
• The Components are interrelated that is the
function of one component is somehow tied
to the functions of the other components
– Example of desktop system

8. • A system has a boundary within which all of
its components are contained and that
establishes the limits of a system, separating
the system from other systems.
Components within the boundary of a system
can be changed. Whereas things outside the
boundary cannot be changed. All of the
components work together to achieve
some overall purpose for the larger system:
the system's main reason for existing.

9. • A System exists within its environment, which is
everything outside the system’s boundary.
• An interface is which interacts with environment
and also interacts within subsystems.
• A System also must face constraints in its
functioning because there are limits(in terms of
speed memory etc). Some of these constraints
are imposed inside the system (memory, speed)
and some imposed by the environment

10. System Concepts
• Decomposition
• Modularity
• Coupling
• Cohesion

11. Decomposition
• Its deals with the breakdown a system into components.
• These components may themselves be systems (subsystems)
and can be broken down into their component as well.
• Decomposition results in smaller and less complex pieces
that are easier to understand than larger, complex pieces.
• Decomposing a system also helps us to focus on one
particular part of a system, making it easier to think of
how to modify that one part independently of the entire
system.

12. Modularity
• The system is dividing into relatively uniform
size.
• Modules can represent a system simply,
making it not only easier to understand. But
also easier to redesign and rebuild.

13. Coupling
• The subsystems are dependent to each other.
• Subsystems should be as independent as
possible.
• If one subsystem fails and other subsystems
are highly dependent on it, the others will
either fail themselves or have problems
functioning

14. Cohesion
• Which tells the subsystem perform a single
function.

15. Organizations, Mangers and Information
• The main purpose of an organization is to
deliver service or product.
– If it is non-profit Ex:-It may deliver service of
educating students about
– If it is profit-oriented ex:-sell the service of fixing
computers
• Whether computer-based or not has to flow
with in a way that will help managers and
organizations achieve their goals

16. Departments
• Organizations have departments that perform
five functions:
– Research and Development(R&D)
– Production
– Marketing
– Accounting and Finance
– Human Resources(Personnel)

17. • Research and Development(R&D) : The R&D
department do two things:
– It conducts basic research, relating discoveries to
the organizations existing or new products.
– It does product development and test and
modifies new products or services created by
researchers
• Production: The production department
produces the product or provides the service.
• Marketing: The marketing department looks after
advertising, promotion and sales. The people in
this department plan, price, advertise, promote
goods or service to customers

18. • Accounting and Finance : The accounting and
finance department handles all financial
matters. It handles cash management, pays
bills and taxes and compiling financial
statements and reports.
• Human Resources : The human resources or
personnel, department finds and hire people
and retire matters.

19. Management Levels
Top Managers :
• The chief executive officer (CEO) or president is the very top
manager.
• Top managers are concerned with long-range, or strategic,
planning and decisions.
• Ex :Determining the company's 10-year goals
Middle Managers :
• plant manager vision manager, sales manager, branch manager
• Middle-level managers make tactical decisions to implement the
strategic goals of the organization. A tactical decision is made
without a base of clearly defined informational procedures
Supervisory Managers:
• Warehouse manager in charge of inventory restocking
• Supervisory managers make operational decisions-predictable
decisions that can be made by following well-defined sets of
routine procedures.

20. COMPUTER -BASED INFORMATION SYSTEM

21. Transaction Processing System(TPS)
• A transaction is a recorded event having to do with routine
business activities.
– This includes everything concerning the product or service in which the
organization is involved: production, distribution, sales, orders. It also
includes materials purchased, employees hired, taxes paid etc.
• A transaction processing system(TPS) is a computer-based
information system that keeps track of the transactions needed
to conduct business.

22. • Features of TPS:
• Input and Output:
– The inputs to the system are transaction data: bills, orders, inventory
etc.
– The output consists processed bills and paychecks.
• For Lower managers: Because TPS deals with day-to-day matters, It
is used by Supervisory managers.
• Produces Detailed Report : A manager at this level typically will
receive information in the form of detail reports.
– A detail report contains specific information about routine activities.
For ex: The information needed to decide whether to restock
inventory.
• One TPS for each department : Each department or functional area
of an organization
- Research & Development, production, marketing, accounting
and finance uses its on TPS.
• Basis for MIS and DSS: The database of transactions stored in a TPS
provides the basis for management information system and
decision support system

23. Management Information System(MIS)
• A Management information system(MIS) is a computer-based
information system that uses data recorded by TPS as input into
programs that produce routine report as output.
• Features of MIS:-
• Input and Output:
– Inputs consist of processed transaction data, such as bills, orders and
paychecks, plus other internal data.
– Output consists of summarized, structured reports.
• For Middle managers:
– An MIS is intended principally to assist middle managers-specially to help
them with tactical decisions.
– It helps them to spot trends and get an overview of current business
activities.
• Draws from all department : The MIS draws from all five
departments.
• Produces several kinds of reports: Managers at this level usually
receive information in the form of several kinds of reports:
summary, exception, periodic and demand.

24. • Summary Reports show totals and trends. For example, a
report showing total sales by office, by product, and by
salesperson as well as total overall sales.
• Exception Reports show out-of-the-ordinary data. For
example, an inventory report listing only those items of
which fewer than 20 are in stock.
• Periodic Reports are produced on regular schedule. Such as
daily, weekly, monthly, quarterly.
• Demand Reports produce information in response to an
unscheduled demand.

25. Decision Support Systems(DSS)
• A decision support system(DSS) is a computer-based information system
that provides a flexible tool for analysis and helps managers focus on
future.
• Whereas a TPS records data and an MIS summarizes data, a DSS analyzes
data.
• Features of DSS:-
• Inputs and Outputs:
– Inputs include internal data-such as summarized reports and processed
transaction data- and also data that is external to the organization
– External data may be produced by trade associations, marketing research firms,
the Indian Bureau of the Census and other government agencies.
• Mainly for Middle managers: A DSS is intended principally to assist
middle managers in making tactical decisions.

26. • Produces analytic models: The key attribute of a DSS is that it
uses models. A model is a mathematical representation of a
real system. The models uses a DSS database, which draws on
the TPS and MIS files, as well as external data such as stock
reports, government reports, and national and international
news. The system is accessed using the DSS software.

27. Executive Support System(ESS)
• An executive support system (ESS) is an easy-
to-use DSS made especially for top managers.

28. Office automation systems
• Office automation systems combine various technologies to
reduce the manual labour in office environment.
• Used throughout all levels of an organization, include fax,
voice mail, e-mail, scheduling software, word processing, and
desktop publishing, among others.
• Ex: Electronic publishing systems.
Electronic Communications Systems

29. Expert Systems
• An Expert System is a set of interactive
computer programs that helps users solve
problems. Uses ‘Artificial Intelligence’

30. • Open Systems, interact freely with their
environments, taking in input and returning output.
As the environment changes, an open system must
adapt to the changes or suffer the consequences.
• A Closed Systems does not interact with the
environment.

31. Chapter 1 Questions
• 2 Marks
1. What is system? Give an example of a system
2. What is a subsystem? What is the other name for a
subsystem
3. Describe the following:
1. Open System
2. Closed System

32. • 5 Marks
1. What is a system? What are its parts? Explain
2. Explain the following system Concepts
1. Decomposition
2. Modularity
3. Coupling
4. Cohesion
3. Explain the features of Transaction Processing System
4. What are the six computer based information system

33. The System Development Life Cycle
• A system is defined as a collection of related
components that interact to perform a task in order
to accomplish a goal
– The system analysis and design is to ascertain how a system works and
then take steps to make it better.
– An organization’s computer-based information system consists of
hardware, software, people, and data as well as communication
setups. These work together to provide people with information for
running the organization.
• There are three types of participants are there in project
– Users: The system under consideration should always be developed in
consultation with users, whether floor sweepers, research scientists,
or customers.
– Indeed, if user involvement in analysis and design is inadequate; the
system may fail for lack of acceptance.

34. • Management. Managers within the organization should also be consulted
about the system.
• Technical staff. Members of the company's information systems (IS)
department, consisting of systems analysts and programmers, need to be
involved
• A System Analyst is an information specialist who performs systems
analysis, design, and implementation.
• The analyst’s job is to study the information and communications needs of
an organization and determine what changes are required to deliver
better information to people who needs it.

35. Systems Development Life Cycle(SDLC)
• System Analysis and Design is a six-phase problem solving
procedure for examining an information system and
improving it. The six phases make up what is known as the
systems development life cycle.
• The systems development life cycle(SDLC) is the step-by-step
process that many organizations follow during systems
analysis and design.
• User input and review is a critical part of each phase

36. Requ
req
3. Systems
design
4. Systems
development
5. Systems
implementation
6. Systems
maintenance
1. Preliminary
investigation
2. Systems
analysis
Figure : SDLC with the analysis phase highlighted

37. Preliminary Investigation
• Preliminary investigation, is to conduct a preliminary analysis,
propose alternative solutions, describe costs and benefits and
submit a preliminary plan with recommendations.
• The steps are:
– Conduct Preliminary analysis: It includes stating the objectives ,
defining nature and scope of the problem.
– Propose alternative solutions.
– Describe costs and benefits of each solution
– Submit a preliminary plan : The readers of this report will be the
executives who are in a position to decide in which direction to
proceed- make no changes, change a little, or change a lot-and how
much money to allow the project.

38. System Analysis
• The objective of phase 2, system analysis, is to gather data,
analysis the data, and write a report.
• The steps are:-
– Gather data, : In gathering data, you will review written documents,
interview employees and managers, develop questionnaires. And
observe people and processes at their place of work.
– Analyse the data: using modelling tools:, Modeling tools enable a
systems analyst to present graphic. Or pictorial. Representations of a
system. charts, data flow diagrams, system flow diagrams
– Write a report : This report to management should have
three parts:
• It should explain how the existing system works.
• It should explain the problems with the existing system.
• It should describe the requirements for the new system and make
recommendations on what to do next.

39. System Design
• The objective of Phase 3, System Design is to do a preliminary
design and then detailed design, and write a report.
• The steps are follows
– Do a preliminary design, using CASE (Computer-Aided Software
Engineer) tools, prototyping tools, and project management software,
among others.
– Do a detail design, A detail design describes how a proposed
information system will deliver the general capabilities described in the
preliminary design. Output requirements
• Input requirements, Storage requirements, Processing requirements, and
System control and back up.
– Write a report. :All the work of the preliminary and detail designs will
end up in a large, detailed report. When you hand over this report to
senior management, you will probably also make some sort of
presentation or speech.

40. System Development
• In Phase 4, systems development, the systems analyst or others in
the organization develop or acquire the software, acquire the
hardware, and then test the system.
The steps are given below:
• (i) Acquire software. : make-or- buy decision, you decide whether
you have to create a program-have it custom-written-or buy it,
meaning simply purchase an existing software package.
• If you decide to create a new program, then the question is
whether to use the organization's own staff programmers or to hire
outside contract programmers (outsource it). Whichever way you
go, the task could take many months.
• (ii) Acquire hardware: Once the software has been chosen, the
hardware to run it must be acquired or upgraded.

41. • (iii) Test the system : Testing is usually done in two stages:
unit testing, then system testing.
– In Unit testing, the performance of individual parts is examined, using
test data.
– In System testing, the parts are linked together, and test data is used
to see if the parts work together.
– At this point, actual organization data may be used to test the system.

42. Systems Implementation
• Phase 5, systems implementation, consists of converting the
hardware, software, and files to the new system and training the
users. The steps are given below:
– Convert to the new system.: Conversion, the process of transition
from an old information system to a new one, requires converting
hardware, software, and files.
• Direct Implementation means that the user simply stops using the old system
and starts using the new one.
• Parallel implementation means that the old and new systems are operated
side by side until the new system has shown it is reliable, at which time the
old system is discontinued. Incase,If the new system fails, the organization
can switch back to the old one.
• Phased implementation means that parts of the new system are phased in
separately-either at different times (parallel) or all at once in groups (direct).
• Pilot implementation means that the entire system is tried out but only by
some users. Once the reliability has been proved, the system is implemented
with the rest of the intended users.

43. – Compile final documentation: Documentation of a system consists of
written description of system's specification, its design, code,
operating procedures etc.
– Documentation for users-it describes how to use the system.
– Documentation for Maintenance Programmers-it is also called
technical documentation and used for system modification at some
later stages. Documentation of a system must start with the system
definition. It is very difficult to think about the documentation in the
end.
– Train the users.

44. Systems Maintenance
• There is a sixth-and never-ending-phase in which the
information system must be monitored to ensure that it is
successful.
• Maintenance includes not only keeping the machinery
running but also updating and upgrading the system to keep
pace with new products, services, customers, government
regulations, and other requirements.

45. System Documentation
• Documentation is a major means of communication.
• It is through the documents that users learn about the system and they
need to refer to the documents to use the system.
• Documentation forms a written record for the work; it establishes design
and performance criteria for the project phases.

46. Standard used to create documents typically address the following:
1. Title page and documents id, along with other identifiers like project name
2. Versions control information
3. Names of author, reviewer, approver
4. Date of release
5. Version number
6. Change control history
7. Table of contents, figures and tables
8. Scope of the documents
9. Expected reader profile
10. Definitions and acronyms
11. Other documents to refer to (specific references)
12. Overview/introduction
13. Summary/conclusions as executive summary, if relevant
14."Main body of the documents
15. Supporting appendices.

47. Waterfall SDLC
• In the waterfall model the process in carried in phases.
• The output of one phase in the waterfall model is the input to the other
phase.
• There are standards set for the output of each process. If one output is
wrong it disturbs the entire model.
• With the help of the waterfall model one can easily measure the progress
of the current project which is carried on.

48. Prototyping Model
A prototype can be built with any computer language or development tool
• Using prototyping as a development technique the analyst works with users to determine
the initial or basic requirements for the system.
•The analyst then quickly builds a prototype.
• When the prototype is completed, the users work with it and tell the analyst what
they like and do not like about it.
• The analyst uses this feedback to improve the prototype and takes the new version
back to the users.
•This interactive process continues until the users are relatively satisfied with what
they have seen.

49. • Two key advantages of the prototyping
technique are the large extent to which
prototyping involves the user in analysis and
design and its ability to capture requirements
in concrete, rather than verbal or abstract.

51. JOINT APPLICATION DESIGN
• It is development methodology system originally
used for designing a computer-based system.
• It involves continuous interaction with the users
and different designers of the system in
development.
• JAD allows for a faster development process and
minimizes errors at the same time.
• JAD also improves the quality of the final product

52. Rapid Application Development
• It is an approach to developing information
systems that promises better and cheaper
systems.
• The ready availability of powerful software
tools created to support RAD.
• RAD tools and software created to support
speedy creation of Web-based applications.

53. Chapter 2
• 2 Marks
1. What is System Development Life Cycle
2. Describe the various types of participants in any types of project.
3. What is documentation.
5 Marks
1. What are the six phases of the System Development Life Cycle (SDLC)?
2. Explain system analysis phase of SDLC
3. What is prototyping? What are the advantages ? How can a prototype be
developed
4. What are the various criticisms to traditional waterfall SLDC? Explain.
5. Explain preliminary investigation phase of SDLC

54. System Analyst
• Definition : System analyst is a person who
studies the problems and needs of an
organization to determine how people, data,
processes, communications and information
technology can best accomplish
improvements for the business.

55. Managers in Systems Development
• The manager of an IS department may have a direct
involvement in the systems development process.
• a manager are more involved in allocating resources
• IS managers may attend some project review meetings
and certainly will expect written status reports on
project progress covering their areas of concern.
• IS managers may prescribe what methodologies,
techniques, and tools are to be used and the procedure
for reporting the status of projects

56. Systems Analysts in Systems
Development
• To succeed as a systems analyst, he/she must develop four
types of skills:
– Analytical enable him/her to understand the organization and
its functions, to identify opportunities and problems, and to
analyze and solve problems.
– Technical him/her understand the potential and the limitations
of information technology.
– An analyst must be able to envision an information system that
will help users solve problems and that will guide the system's
design and development.
– He/she must also be able to work with programming languages,
various operating systems, and computer hardware platforms.

57. – Managerial help him/her manage projects, resources, risk,
and change.
• Project risk is an uncertain event or condition that, if it occurs, has
an effect on at least one project objective.
– Interpersonal help him/her work with end users as well as
with other analysts and programmers. Effective written
and oral communication, including competence in leading
meetings, interviewing, and listening, is a key skill analysts
must master. Effective analysts successfully combine these
four skills.

58. Programmers in Systems
Development
• Programmers convert the system
specifications given to them by the analysts
into instructions the computer can
understand.
• Writing a computer program is sometimes
called writing code, or coding. Programmers
also write program documentation and
programs for testing systems.

59. Business Managers in Systems
Development
• These managers are very important to systems development
because they have the power to fund development projects
and to allocate the resources necessary for the projects'
success.
• Because of their decision-making authority and knowledge of
the firm's lines of business, department heads and executives
are also able to set general requirements and constraints for
development projects.

60. Other IS Manager is Technicians in
Systems Development
• In larger organizations where IS roles are more differentiated,
there may be several additional IS professionals involved in
the systems development effort.
• A firm with an existing set of databases will most likely have a
database administrator who is usually involved in any systems
project affecting the firm's databases.
• Network and telecommunication experts help develop
systems involving data and/or voice communication, either
internal or external to the organization.

61. Analytical skills for system analysts
1. Systems Thinking
– The first step in systems thinking is to be able to
identify something as a system.
– Identify where the boundary lies and all of the
relevant inputs.
– Visualizing a set of things and their relationship
as system

62. 2. Organizational Knowledge
– As a systems analyst has to work in organizations.
– Whether he/she is an in-house analyst or a contact custom software
developer, he/she must understand how organizations work
– In addition he/she must understand the functions and procedures of
the particular organization(or enterprise) he/she is working for.
– The various kinds of organizational knowledge that a
systems analyst must acquire in order to be successful is
given below:-
• Understanding of how organizations work
• Knowledge of specific functions and procedures of
organization and department
• How work officially gets done
• Internal policies
• Competitive Environment
• Organizational Strategies and Tactics

63. 3. Problem Identification
– Problem is the difference between an existing
(current) situation and desired (output) situation.
– The process of identifying problems is the process
of defining differences, so problem solving is the
process of finding a way to reduce differences.
– Analyst should able to compare the current in an
organization to the desired situation

64. 4. Problem Analysing and Solving
– Once a problem has been identified, a systems
analyst must analyze the problem and determine
how to solve it.
– Systems analysts learn through experience, with
guidance from proven methods, how to get the
needed information from people as well as from
organizational files and documents.
– he/she also begins to formulate alternative
solutions to the problem

65. TECHNICAL SKILLS FOR SYSTEM ANALYSTS
• Technical skills help you understand the potential and limitations of
information technology.
• As an analyst, you must be able to envision an information system that will
help users solve problems and that will guide the system’s design and
development.
• You must also be able to work with programming languages, various
operating systems, and computer hardware platforms.
• Understanding of a wide variety of technologies is required
– Microcomputers, workstations, minicomputers and mainframe computers
– Programming languages
– Operating systems
– Database and file management systems
– Data communication standards
– Systems development tools and environments
– Web development languages and tools
– Decision support system generators

66. Management Skills for System Analysts
Management skills are very useful for anyone in a
leadership role.
1. Resource Management
• A systems analyst must know how to get the most out of a wide
range of resources: system documentation, information
technology, and money.
• For an analyst leading a team, the most important resource is
people.
• A team leader must learn how to best use the particular talents
of other team members.
• A team leader must also be able to delegate responsibility,
empowering people to do the tasks they have been assigned.

67. 2. Project Management
– Effectively managing projects is crucial to a systems
analyst's job.
– The goal of project management is to prevent projects
from coming in late and going over budget.
– In addition project management is designed to help
managers keep track of the project's progress.
3. Risk Management
– Once risks to the project have been identified, a systems
analyst must be able to minimize the likelihood that those
risks will actually occur.
– The goal of project management is to prevent projects
from coming in late and going over budget.
– If minimizing risk is not possible, then he/she tries to
minimize the damage that might result.

68. 4. Change Management
– System Analyst must know how to get people to
make a smooth transition from one formation
system to another, giving up their old ways of
doing things and accepting new ways.
– Change management also includes the ability to
deal with technical issues related to change, such
as obsolescence and reusability.

69. Interpersonal Skills for System Analysts
1. Communication Skills
– The single most important interpersonal skill for
an analyst, as well as for any professional, is the
ability to communicate clearly and effectively
with others.
– Analysts should be able to successfully
communicate with users, other information
systems professionals. and management.

70. Interviewing and Listening
– Interviewing is one of the primary ways analysts
gather information about an information systems
project.
– There are many ways to effectively interview
someone, and becoming a good interviewer takes
practice.
– It is important to point out that asking questions is
only one part of interviewing.
– Careful listening helps him/her understand the
problem
Written and Oral Presentations

71. 2. Working Alone and with a Team
– As a systems analyst, he/she must often work alone
on certain aspects of any systems development
project.
– To this end, he/she must be able to organize and
manage his/her own schedule, commitments, and
deadlines.
– Many people in the organization will depend on
his/her individual performance, yet he/she is almost
always a member of a team and must work with the
team toward achieving project goals.

72. 3. Facilitating Groups
– Sometimes a systems analyst needs to interact
with a group in order to communicate and receive
information.
3. Managing Expectations
– Organization members will have certain ideas,
perhaps based on their hopes and wishes, about
what a new information system will be able to do
for them; these expectations about the new
system can easily run out of control.
– It is found that successfully managing user expectations is
related to successful systems implementation.

73. • 5 Marks
1)What are system analysts role and responsibility in large
and small organizations
2) List and explain technical skills for system analysts
3) Describe the management skills for system analysts
4) Why a system needed in an organization
5) Explain interpersonal skills for system analysts
6) Describe the functions and activities of managers of an
information system
7) Describe the analytical skills for system analysts