Upload
s-a-ahsan-rajon
View
225
Download
0
Embed Size (px)
Citation preview
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 1/53
S. A. AHSAN RAJON
http://sites.google.com/site/ahsanrajon
+88-01911510286
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 2/53
S. A. AHSAN RAJON 2
� SAD
System Analysis and Design
� ISAD
Information System Analysis and Design
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 3/53
S. A. AHSAN RAJON 3
� Easy course; but uninteresting;
No math; No programming; No logic;
Simply ́ voluminousµ texts.
� Traditional learning«
� How to do well in exam?
Understand the topic«
Note down the ´Key pointsµ extracted from the texts.
Try to match with your usual ´day-to-dayµ concept.
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 4/53
S. A. AHSAN RAJON 4
� At LEAST THREE class tests«
If you want more; ... [ ??? ]
� Class Test Schedule
� Week will be fixed by me«.
� Dates will be SELECTED by you
� DATES are absolute; not even ask«
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 5/53
S. A. AHSAN RAJON 5
� BOOKS
SYSTEMS ANALYSIS AND DESIGN
� Author: Elias M. Awad
� Edition: Second Edition or Any recent
� Publisher: Galgotia Publications
Modern System analysis and Design
� Author: Jeffery A. Hoffer, Joey F. George, Joseph S. Valacich, Prabin K.
Panigrahi
� Edition: Fourth Edition or recent
� Publisher: Pearson
SYSTEM ANALYSIS AND DESIGN METHODS
� Author: Jeffery L. Whitten
� Edition: Fifth Edition or recent
� Publisher: McGraw Hill
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 6/53
S. A. AHSAN RAJON 6
� Reference Book
Information Systems: A Management Perspective
� Author: Steven Alter
� Edition: Third Edition or Any recent
� Publisher: Pearson Education
� OTHER RESOURCES
Should be provided
� Lecture Slides
Oops!! SAD with SAD lecture Slides«
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 7/53
S. A. AHSAN RAJON 7
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 8/53
S. A. AHSAN RAJON 8
� Systems Concepts
� System Development Life Cycle
� Role of System Analyst
� System planning
� Information gathering
� Tools for structured analysis
� Cost and benefit analysis
� System and system-component design
� Miscellaneous
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 9/53
S. A. AHSAN RAJON 9
� Software Systems are based on Information Systems
Development of Software requires understanding the ´existing
system set-upµ
Revealing existing set up requires you to understand the
organizational paradigm.
� How to have requirement Analysis?
Then you need data collection
�
How to collect data?
� How to record Data?
� How to get a result from that data?
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 10/53
S. A. AHSAN RAJON 10
� Consider
University Management System.
Employee information and Payroll management System.
Company Automation System/production control system
National ID project.
Electronic voting system.
SMS-based information management system.
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 11/53
S. A. AHSAN RAJON 11
� For any System
What is the current system?
How the current system works?
What are the advantages & disadvantages i.e. problems of
present system?
How Information Technology may be applied (if not applied in
the current system)?
� Or how the adopted Information Technology based System may be
enhanced?
Which advantages are obtained by applying the new systems.
� What are the limitations/disadvantages/pitfalls of new systems?
How to administer/Manage the new system?
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 12/53
S. A. AHSAN RAJON 12
� Derived from Greek word ´systemaµ which means
An organized relationship among functioning units or
components.
A system exists because it is designed to achieve one or
more objectives.
� A system is an orderly grouping of interdependent
components linked together according to a plan to
achieve a specific objective.
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 13/53
S. A. AHSAN RAJON 13
� Component may refer to
Physical parts
� engines, wings of aircraft or wheels of a car
Managerial steps
� Planning, Organizing, Directing and Controlling
Or a subsystem of multilevel structure
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 14/53
S. A. AHSAN RAJON 14
� Components of a system may be simple or
complex , basic or advanced .
� There may be a single computer or even be a
series of intelligent terminals linked to amainframe.
In either case, each component is part of the total system
and has to share do its share of work for the system to
achieve the intended goal.
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 15/53
S. A. AHSAN RAJON 15
� A system must be designed to achieve a
predefined objective.
� I
nterrelationships and interdependence mustexist among the components.
� The objectives of the organization as a whole hasa higher priority than the objectives of the
subsystem.
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 16/53
S. A. AHSAN RAJON 16
� Organization
� Interaction
� Interdependence
� Integration
� Central Objective
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 17/53
S. A. AHSAN RAJON 17
� Implies Structure and Order
� Arrangements that helps to achieve objectives
� Hierarchical Relationship
Such Arrangement portraying a system³subsystem
relationship
Defines authority structure
Specifies formal flow of communication
Formulizes the chain of command
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 18/53
S. A. AHSAN RAJON 18
� Refers to the manner in which each component
functions w ith other components of the system.
Interrelationship among the central processing unit,
memory and other hardware components enables the
computer system to perform.
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 19/53
S. A. AHSAN RAJON 19
� Interdependence means that parts of the
organization or computer system w orks together .
� They are coordinated and linked together
according to a plan.� One subsystem depends on input o f another
subsystem f or proper functioning; that is output
of one subsystem is required input of anothersubsystem.
� N o subsystem can function in isolation.
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 20/53
S. A. AHSAN RAJON 20
� Task interdependence in computer based systems
Userarea
System
AnalysisDesign
Programm
ing
Operatio
ns
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 21/53
S. A. AHSAN RAJON 21
University
Admission
Administra
tion
personnel
Finance
Courses
personnel
Employm
ent
Accounts
Safety
Miscella
neous
Benefits
Accounts
Grants
Internal
earnings
Consulta
ncy
Researc
hOutcome
Major Subsystem
Intermediate Subsystem
Minor Subsystem
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 22/53
S. A. AHSAN RAJON 22
� Refers to the holism of a system.
� Integration is concerned with how a system is
tied together .
� More than sharing a physical part.
� It means that parts of the system works together
within the system even though the each part
per f orms a unique function.
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 23/53
S. A. AHSAN RAJON 23
� Objectives may be real or stated.
� Achievement of one objective may be a must for
moving towards achievement of another one.
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 24/53
S. A. AHSAN RAJON 24
� An information system is an
arrangement of people, data, process, information
presentation and information technology
that interact to support an improved day-to-day operations
in a business
as well as support the problem solving and decision making
needs to management and users.
[Whitten]
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 25/53
S. A. AHSAN RAJON 25
� Information system may be defined as
a set of devices, procedures and operating systems
designed around user based criteria to produce information
and
communicate it to the users
for planning, control and performance
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 26/53
S. A. AHSAN RAJON 26
� Information technology is a contemporary term
that describes the combination of computer
technology (hardware and software) with
telecommunication technology (data, voice
networks)
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 27/53
S. A. AHSAN RAJON 27
� Information system analysis and design is the complex
organizational process whereby computer basedorganizational systems are developed and maintained.
� Main goal is to improve employee efficiency by applying
software solutions to key business tasks
� A structured approach must be used in order to ensure
success
[ Hoffer ]
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 28/53
S. A. AHSAN RAJON 28
� Types of Systems
Physical and abstract
Open or closed
Man-made information system
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 29/53
S. A. AHSAN RAJON 29
� PHYSICAL SYSTEMS«
T angible entities; may be static or dynamic in operation
� E.g. in computer centers, computer hardware are static,
programs stored into computers are dynamic
Data, programs, output and applications change as users·
demands
� ABSTRACT SYSTEMS
Conceptual or non-physical entities
� E.g. model; representation of real or planned systems.
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 30/53
S. A. AHSAN RAJON 30
� TYPES of SYSTEM MODELS
Schematic Model
� Two dimensional chart describing system elements and linkage
Flow-System Model
� Concerned with flow of information
Static system model
� Exhibits pair relationship; e.g. activity-time or cost-quantity
� Gantt chart
Dynamic System Model
� Describes ongoing consistently changing system
� Trend analysis, probabilistic model.
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 31/53
S. A. AHSAN RAJON 31
� Open Systems
Permits interactions across its boundaries.
Receives input from and delivers output to outside.
Information system falls into this category since it must
adapt to the changing demands of the user.
� Closed Systems
Isolated from environmental influences.
In reality completely closed system is rare.
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 32/53
S. A. AHSAN RAJON 32
� CHARACTERISTICS OF OPEN SYSTEMS
Input from outside
Entropy
Process, Output and Cycles
Differentiation
Equi-finality
� No matter how you reach the destination; the matter is, the
costs and outcome would be the same.
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 33/53
S. A. AHSAN RAJON 33
� Input from outside
Open Systems are Self adjusting and self adapting
When functioning properly Open Systems reaches into
Steady State or equilibrium
� Entropy
All dynamic systems tend to run down over time resulting
in entropy or loss of energy
Open systems resist entropy by seeking new inputs or
modifying the processes to return to a steady state.
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 34/53
S. A. AHSAN RAJON 34
� Process, Output and Cycles
Produce output, operate in cycles, follows continuous
processing path
� Differentiation
Have a tendency towards an increasing specialization of
functions
� Equi-finality
Implies that, goals are achieved through differing courses
of actions and a variety of paths.
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 35/53
S. A. AHSAN RAJON 35
� Man-Made Information systems
Recall definition of information systems.
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 36/53
S. A. AHSAN RAJON 36
� Types of (Man-made) Information System
Formal Information Systems
Informal Information Systems
Computer-based Information Systems
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 37/53
S. A. AHSAN RAJON 37
� Based on organization based on organization
represented by the organization chart
This chart is a Map of positions and their authority relationships,
indicated by boxes and connected by straight lines.
� concerned with the pattern of authority,
communication and work flow
� Information is formally disseminated in instructions,
memos or reports from top management to the
intended users in the organizations� Also allows feedback up the chain of command for
follow-up.
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 38/53
S. A. AHSAN RAJON 38
� Organizational charts depict the hierarchy of
employees in an organization
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 39/53
S. A. AHSAN RAJON 39
� STRATEGIC INFORMATION
Refers to long range planning policies that are of direct
interest to upper management.
Information such as trends in financial investment, human
resources changes would be of top company officials who
are responsible for developing policies and determining
long range goals.
� This type of information is achieved by DECISION SUPPORT SYSTEM (DSS)
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 40/53
S. A. AHSAN RAJON 40
� MANAGERIAL INFORMATION
Of direct use to middle management and department
heads for implementation and control
� E.g. sales analysis, cash flow projections, financial statements
This type of information is of use in short and
intermediate range planning.
� Maintained with the aid of Management Information System
(MIS)
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 41/53
S. A. AHSAN RAJON 41
� OPERATIONAL INFORMATION
Short term; daily information used to operate
departments and enforce day to day rules and regulations
of the business.
� E.g. daily employee absence sheets, overdue purchase orders,
current stock available for sale
� Operational information is established by Data Processing
Systems (DPS)
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 42/53
S. A. AHSAN RAJON 42
Strategic
Planning Information
Management control information
Operational information
UPPER
MIDDLE
LOWER
DSS
Decision Support System
MIS
Management
Information System
DPS
Data Processing
System
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 43/53
S. A. AHSAN RAJON 43
� employee based system
designed to meet personal and vocational needs and to help solvework related problems.
� Knowledge about the inner working of the employee based
system is useful during the exploratory face of the
analysis. Employee co-operation and participation are crucial in training users.
� Since computer can·t provide reliable information without
user staff support, a proper interface with the informalcommunication channels could mean the difference the
between the success and the failure of the system.
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 44/53
S. A. AHSAN RAJON 44
� A third class of the information system realize
on the computer for handling the business
applications.
Transaction processing system (TPS)
Management Information System (MIS):
Decision Support System (DSS)
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 45/53
S. A. AHSAN RAJON 45
� The level of the manager in the organization is an
important factor in determining the kind of informationneeded to solve a problem.
Lower level management needs detailed internal information to make
day to day relatively structured controlled decisions higher level
management.
For whom the long range objectives are the primary concerns requires
summarized information from a variety of sources to attain goals.
� MIS is a person machine system and a highly integrated
grouping of information processing function designed to
provide management with a comprehensive picture ofspecific information of specific operations.
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 46/53
S. A. AHSAN RAJON 46
� The primary users of MIS are middle and top management,
operational managers and support staff.� Middle and top management use MIS for
preparing forecasts,
special request for analysis
long range plans and
periodic reports.
� Operational managers use MIS primarily for
short range planning and
periodic and exception reports.
� The support staff finds MIS useful for the
special analysis of information and
reports to help management in planning and control.
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 47/53
S. A. AHSAN RAJON 47
� MIS provides limited support to top level management
for decision making whereas DSS advances the capabilitiesof MIS.
It assists management in making decisions.
� Decision support system stands for ²
Decision
� emphasizes decision making in problem situation.
Support
� Requires computer added decision situation enough structure to
permit computer support.
System
� Combines the integrated nature of problem solving suggesting a
combine ¶man· , machine and decision involvement.
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 48/53
S. A. AHSAN RAJON 48
� DSS results from adding
external data sources,
accounting and statistical models and
interactive query capabilities.
� The outcone is a system designed to serve all
levels of management and top level
managements in particular with ´w hat i f µunstructured problem situation.
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 49/53
S. A. AHSAN RAJON 49
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 50/53
S. A. AHSAN RAJON 50
� Harvard Simon described decision making as a
three phase continuous process model.
Pro lem Recognition
Gathering
information a out a
pro lem
Calling for a decision
Develop alternative
Solutions
Evaluate Alternative
Solutions
Actual Selection of
a solution for
implementation
Intelligence Design Choice
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 51/53
S. A. AHSAN RAJON 51
� Expert systems are designed to analyze data and
produce a recommendation, diagnosis, or decisionbased on a set of facts and rules
Knowledge base
� Inference engine
� Knowledge engineering Expert system shell
Fuzzy logic
� A neural network uses computer circuitry to
simulate the way a brain might processinformation, learn, and remember
8/6/2019 01 Isad Intro Rajon
http://slidepdf.com/reader/full/01-isad-intro-rajon 52/53
S. A. AHSAN RAJON 52
An expert system is
characterized y its a ility to:
Replicate the reasoning
of a human expert
Work with internal or
external data
Produce a
recommendation or
decision