Transcript No Slide Title

Major Topics
•
•
•
•
•
Information systems
Integrating New Technology
Phases of analysis and design
System maintenance
CASE tools
Information
• Information is an organizational resource
which must be managed as carefully as
other resources
• Costs are associated with information
processing
• Information processing must be managed
to take full advantage of its potential
Categories
• Eight categories of Information systems:
•
•
•
•
•
•
•
•
Transaction processing systems (TPS)
Office automation systems (OAS)
Knowledge work systems (KWS)
Management information systems (MIS)
Decision support systems (DSS)
Expert systems (ES)
Group decision support systems (GDSS)
Executive support systems (EES)
Level of Categories
Figure 1.1 :The
computer
analyst may be involved
with any of or all these
systems
Transaction Processing Systems
(TPS)
• TPS are computerized information
systems developed to process large
amount of data for routine business
transactions
• TPS reduces the time once required to
perform the task manually
• TPS permits the organization to interact
with external environment
• Example: Inventory or Payroll system
Office Automation Systems (OAS) and Knowledge Work Systems
(KWS)
• Office Automation Systems (OAS):
– Includes analysis of information so as to transform
data or manipulate it in some way before sharing or
formally disseminating it
– Example: Word processing, spreadsheets, desktop
publishing, electronic scheduling, communication
through voice email, email and voice conference
etc.
• Knowledge Work Systems (KWS):
– Supports professionals (scientists, engineers,
doctors) by aiding them to create new knowledge
– Example: Scientific analysis
Management Information Systems
(MIS)
• MIS supports broader spectrum of
organizational tasks than TPS, including
decision analysis and decision making
• MIS users share a common database to
access information
• MIS outputs information that is used in
decision making
• Example: Account management system
of
Internet users
Decision Support systems
(DSS)
• DSS is similar to the traditional MIS
because they both depend on a database
as a source of data
• Again, DSS departs from MIS in that
DSS emphasizes the support of decision
making in all its phases
• Example: Production increase decision
by
trend analysis
Expert Systems
• Expert system is a very special class of
information system which is capable of
generating solutions to problems with the
aid of Artificial Intelligence (AI)
• An expert system (also called a
knowledge based system) uses the
knowledge of an expert for solving a
particular problem
• Example: News Categorization software
Group Decision Support Systems (GDSS) and
Computer Supported Collaborative Work Systems (CSCWS)
• Group Decision Support Systems
– GDSS are intended to bring a group together to
solve a problem with the help of various support
such as polling, questionnaires, brainstorming etc.
• Computer Supported Collaborative Work
Systems
– CDCWS is a more general term of GDSS
– CSCWS may include software support called
“groupware” for team collaboration via network
computers
• Example: video conferencing and web survey
system
Executive Support Systems
(ESS)
• It helps executives to make decisions on
strategic level
• It may provide graphical representation
and communication support at board
meeting required to make strategic
decision
• Example: New product launching
decision
Integrating New Technologies
• New technologies are being integrated
into traditional systems
• E-commerce uses the Web to perform business
activities
• Enterprise Resource Planning (ERP) has the
goal of integrating many different information
systems within the corporation
• Wireless and handheld devices, including
mobile commerce (m-commerce)
• Open source software
Integrating New Technologies
Figure 1.2: Integrating
Technologies
E-Commerce Application and Web Systems
Many businesses has found The Internet
as
their most favored way to pursue business
growth because of the following
advantages:
– Increase awareness of the availability of the
service, product, industry, person, or group
– 24-hour access for users
– Standardizing the design of interface
– Creating a global system rather than remain
Enterprise Resource Planning (ERP)
Systems
• Many organizations predicts potential
benefits from the integration of many
information systems existing on different
management levels.
• ERP systems are designed to perform
this integration
• Example: SAP, PeopleSoft and packages
from Oracle
Systems for Wireless and Handheld
Devices
• System analyst may be asked to design
standard or wireless communication
network that integrate voice, video and
email into organizational intranet
• System analyst may also be asked to
develop intelligent agents to assist the
user of PDA or cell phone
• Wireless communication is referred as mcommerce (mobile commerce)
Open Source Software
• An alternative of traditional software
development (where proprietary code is hidden
from the users) is called open source software
• Open source software is free to distribute,
share and modify its source code
• It makes money by providing services,
customized program and support.
• Open source software are widely used in
handheld and mobile devices.
• Example: Linux Operating System
Apache Web Server
Nature of Analysis and
Design
• A systematic approach to:
– identify problems, opportunities, and
objectives;
– analyze the information flows in
organizations; and
– design computerized information systems
to solve a problem.
Systems Analyst
• Systems analysts act as:
– Outside consultants to businesses
– Supporting experts within a business
– Change agents
• Analysts are problem solvers, and
require communication skills
• Analysts must be ethical with users and
customers
Systems Development Life Cycle
(SDLC):
• SDLC is a systematic approach for solving
business problems.
• It is divided into seven phases.
• Although each phase is presented
discretely, it is never accomplished as a
separate step. Instead separate activity
can occur simultaneously
Systems Development Life Cycle
(SDLC):
Figure 1.3: Phases of SDLC
Phase 1: Identifying Problems, Opportunities and Objectives
• Personnel involved:
– Analyst
– User management
– System management
• Activities:
– Interviewing user management
– Summarizing the knowledge obtained
– Estimating the scope of the project
– Documenting the results
• Output: Feasibility report containing problem definition and
objectives
• Decision: Management then make decision whether to
proceed with
the proposal or not
Phase 2: Determining Information Requirement
• Personnel Involved:
– Information Analyst (IA)
– User: operation managers and operation workers
– Systems management
• Activity:
–
–
–
–
–
Interview management, operations personnel
Gather systems/operating documents
Use questionnaires
Observe the system and personnel involved
Learn the who, what, where, when, and how, and the why for
each of these
• Output: Analyst understands how the business functions
and
gets enough information about the people,
goals,
data and procedure involved
Phase 3: Analyzing System
Needs
• Personnel Involved:
– Analyst (IA)
– User management
– Systems management
• Activity:
–
–
–
–
–
–
Create data flow diagrams
Document procedural logic for data flow diagram processes
Complete the data dictionary
Make semi-structured decisions (condition alternatives)
Prepare and present the system proposal
Recommend the optimal solution to management
Phase 4: Designing the Recommended
System
• Personnel involved
–
–
–
–
Analyst
System designer
User: operation managers and operation workers
System management
• Activity:
– Design the user interface
• Design output
• Design input
–
–
–
–
–
Design system controls
Design files and/or database
Produce program specifications
Produce decision trees or tables
Backup procedure
Phase 5: Developing and Documenting Software
• Personnel involved
–
–
–
–
Analyst
System designer
Programmers
Systems management
• Activity:
– System analyst designs computer programs using
structure charts, and pseudo code etc.
– Programmers write computer programs
– Document software with help files, procedure
manuals, and Web sites with Frequently Asked
Questions
Phase 6: Testing and Maintaining the System
• Personnel involved
–
–
–
–
Analyst
System designer
Programmers
Systems management
• Activity:
–
–
–
–
Test and debug computer programs
Test the computer system
Enhance system
Maintenance of the system begins from this phase
Phase 7: Implementing and Evaluating the
System
• Personnel involved:
–
–
–
–
–
Analyst
System designer
Programmers
User: operation managers and operation workers
Systems management
• Activity:
– Train users
– Analyst plans smooth conversion from old system to
new system
– Purchase and install new equipment
– Install system
– Review and evaluate system
Maintenance
• Maintenance is performed for 2 reasons:
– System maintenance
• Removing undetected errors, and
• Enhancing existing software
– Systems are enhanced for the following
reasons:
• Adding additional features to the system
• Business and governmental requirements
change over time
• Technology, hardware, and software are rapidly
changing
Impact of Maintenance
Figure 1.4: Time spent on system maintenance
Impact of Maintenance
Figure 1.5: Resource consumption over the
system life
CASE Tools
– CASE tools are automated,
microcomputer-based software
packages for systems analysis and
design
– Four reasons for using CASE tools are:
• To increase analyst productivity
• Facilitate communication among analysts
and users
• Providing continuity and integrity among life
cycle phases
• To assess the maintenance changes
CASE Tool Categories
• CASE tools may be divided into several
categories
– Upper CASE (also called front-end CASE)
tools, used to perform analysis and design
– Lower CASE (also called back-end CASE).
These tools generate computer language
source code from CASE design.
– Integrated CASE, performing both upper
and lower CASE functions.
Upper CASE
• Upper CASE tools
– Create and modify the system design
– Store data in a project repository
– The repository is a collection of records,
elements, diagrams, screens, reports, and
other project information
– These CASE tools model organizational
requirements and define system
boundaries
Upper Case
Figure 1.6: The repository concept
Lower CASE
• Lower CASE tools generate computer
source code from the CASE design
• Source code may usually be generated
in several languages
• Advantages of generation code:
– decrease development time
– More programming language support
– Free from program coding error
Traditional VS Case system development life cycle
Figure 1.7: Traditional VS Case SDLC
Reverse Engineering
• Reverse engineering is generating
the CASE design from computer
program code
• Source code is examined, analyzed,
and converted into repository entities
Advantages of Reverse
Engineering
– Reduced system maintenance time, freeing up
time for new development
– Program documentation is produced for loosely
documented programs
– Structured programs may be generated from
unstructured, older programs
– Future system maintenance is easier to
implement
– Unused portions of programs may be eliminated
Object-Oriented Analysis and Design
• Object-oriented (O-O) analysis and
design is used to build object-oriented
programs
• This includes not only data but the
instructions about operations that
manipulate the data
Alternative Methodologies
Alternatives to SDLC:
– Prototyping
– ETHICS
– Soft System Methodology
– Multiview
1.41