Transcript Chapter 1 Study Tool - Tennessee State University

Systems Analysis & Design
7th Edition
Chapter 1
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Chapter Objectives
 Discuss the impact of information technology
on business strategy and success
 Define an information system and describe its
components
 Explain how profiles and models can represent
business functions and operations
 Explain how the Internet has affected business
strategies and relationships
 Identify various types of information systems
and explain who uses them
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Chapter Objectives
 Explain modeling, prototyping, and CASE tools
 Distinguish between structured analysis and
object-oriented analysis
 Compare the systems development life cycle
waterfall model to adaptive models
 Discuss the role of the information technology
department and the systems analysts who
work there
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Introduction
 Companies use information
as a weapon in the battle to
increase productivity,
deliver quality products
and services, maintain
customer loyalty, and make
sound decisions
 Information technology can
mean the difference
between success and
failure
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The Impact of Information
Technology
 Information Technology
– Combination of hardware and software
products and services that companies
use to manage, access, communicate,
and share information
– A vital asset that must be used
effectively, updated constantly, and
safeguarded carefully
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The Impact of Information
Technology
 The Future of IT
– Accounts for almost 30 percent of
America’s economic growth, and the
wage gaps between IT workers and all
other workers will continue to widen
– Global online population skyrocketed
between 2000 and 2005
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The Impact of Information
Technology
 The Role of Systems Analysis and
Design
– Systems Analysis and Design
• Step-by-step process for developing highquality information systems
– Systems Analyst
• Plan, develop, and maintain information
systems
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The Impact of Information
Technology
 Who develops Information Systems?
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In-house applications
Software packages
Internet-based application services
Outsourcing
Custom solutions
Enterprise-wide software strategies
How versus What
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Information System Components
 A system is a set of related
components that produces
specific results
 A mission-critical system is
one that is vital to a
company’s operations
 Data consists of basic facts
that are the system’s raw
material
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Information System Components
 Hardware
– Moore’s Law
 Software
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System software
Application software
Enterprise applications
Horizontal system
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Information System Components
 Software
– Vertical system
– Legacy systems
 Data
– Tables
– Linking
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Information System Components
 Processes
– Define the tasks and business functions that
users, managers, and IT staff members
perform to achieve specific results
 People
– Users, or end users, are the people who
interact with an information system, both inside
and outside the company
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Understanding The Business
 Business Process Modeling
 Business Profile
 Business Models
– Business model
– Business process
– Business process reengineering (BPR)
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Understanding The Business
 New Kinds of Companies
– Production-oriented
– Service-oriented
– Internet-dependent
– Dot-com (.com)
– Brick-and-mortar
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Impact of the Internet
 E-Commerce or I-Commerce
 B2C (Business-to-Consumer)
 B2B (Business-to-Business)
– EDI
– Extensible markup language (XML)
– Supplier relationship management (SRM)
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Impact of the Internet
 Web-Based System Development
– WebSphere
– .NET
– Web services
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How Business Uses Information
Systems
 In past, IT managers divided systems
into categories based on the user group
the system served
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Office systems
Operational systems
Decision support systems
Executive information systems
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How Business Uses Information
Systems
 Today, it makes more sense to identify a
system by its functions, rather than by
users
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Enterprise computing systems
Transaction processing systems
Business support systems
Knowledge management systems
User productivity systems
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How Business Uses Information
Systems
 Enterprise computing
systems
– Support company-wide operations
and data management
requirements
 Transaction processing
systems
– Efficient because they process a
set of transaction-related
commands as a group rather than
individually
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How Business Uses Information
Systems
 Business support
systems
– Provide job-related
information to users at all
levels of a company
– Management information
systems (MIS)
– Radio frequency identification
(RFID)
– What-if
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How Business Uses Information
Systems
 Knowledge management systems
– Called expert systems
– Simulate human reasoning by combining a
knowledge base and inference rules
– Many use fuzzy logic
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How Business Uses Information
Systems
 User productivity systems
– Technology that improves productivity
– Groupware
 Information systems integration
– Most large companies require systems that
combine transaction processing, business
support, knowledge management, and user
productivity features
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Information System Users and Their
Needs
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Information System Users and Their
Needs
 Top managers
 Middle Managers and Knowledge
Workers
 Supervisors and Team Leaders
 Operational Employees
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Systems Development Tools and
Techniques
Tools
 Modeling
– Models are used to describe and simplify an IS
 Prototyping
– Test system concepts
 Computer-Aided Systems Engineering
– CASE tools
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Systems Development Tools and
Techniques
Modeling
– Business/Requirements model: Information the
systems must provide (Ch 3)
– Data model : how data is represented and
accessed (ch. 4)
– Object model: describe objects which combine
data and processes
– Network model: the design and protocols of
networks
– Process model: outlines the logical processes
and their interrelationships (Ch 4)
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Systems Development Tools and
Techniques
 Prototyping
– Prototype
– Speeds up the development process
significantly
– Important decisions might be made too early,
before business or IT issues are thoroughly
understood
– Can be an extremely valuable tool
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Systems Development Tools and
Techniques
 Computer-Aided Systems Engineering
(CASE) Tools
– Also called computer-aided software
engineering
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Systems Development Methods
 Alternatives:
– Systems development life cycle (SDLC)
• Traditional approach
– Object-oriented analysis (O-O)
• Newer approach
– Mixed method
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Systems Development Methods
 Structured Analysis
– Systems development life cycle (SDLC)
– Uses a series of phases: Plan, Analyze,
Design, Implement, Support
– Predictive approach
– Process-centered technique
– Uses a set of process models to describe a
system graphically
• Process models – identify data flowing into a process,
rules for transformation, and output flows
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Systems Development Methods
 Sample Process model
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Systems Development Methods
 Object-oriented Analysis
– O-O analysis combines data & processes into
objects
– Object is a member of a class
– Objects possess properties
– Methods change an object’s properties
– A message requests specific behavior or
information from another object
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Systems Development Methods
 Object-oriented Analysis
The PERSON class includes
INSTRUCTOR and
STUDENT objects,
which have their own
properties and inherited
properties.
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Planning and Modeling a Systems
Development Project
 In addition to
selecting a
development
method, system
developers also
must create a plan
or model for the
many tasks that
will be required
 Typically, the
development team
will use project
management tools
to help achieve
the end result
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Planning and Modeling a Systems
Development Project
 The SDLC Waterfall Model
The phases and deliverables of the
SDLC are shown in the waterfall model.
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Planning and Modeling a Systems
Development Project
 The SDLC Waterfall Model
– Disadvantage in the built-in structure of the
SDLC, because the waterfall model does not
emphasize interactivity among the phases
– This criticism can be valid if the SDLC phases
are followed too rigidly
– However, adjacent phases usually interact
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Planning and Modeling a Systems
Development Project
 Adaptive approach – spiral development
model
builds on a series of
iterations.
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Planning and Modeling a Systems
Development Project
 Adaptive Methods and Models
– Attempt to develop a system incrementally, by
building a series of prototypes and constantly
adjusting them to user requirements
– Extreme Programming (XP)
– Analysts should recognize that these
approaches have advantages and
disadvantages
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Planning and Modeling a Systems
Development Project
 The SDLC Waterfall Model
– Usually includes five steps
• Systems planning
• Systems analysis
• Systems design
• Systems implementation
• Systems operation, support, and security
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Planning and Modeling a Systems
Development Project
 Systems planning
– Systems request
– Purpose of this phase is to perform a
preliminary investigation whose key part is a
feasibility study
 Systems Analysis
– First step is requirements modeling
– End product is the System requirements
document
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Planning and Modeling a Systems
Development Project
 Systems Design
– Identify all outputs, inputs, and processes
– End product is system design specification
 Systems Implementation
– New system is constructed
– Users, managers, IT staff trained to operate
and support the system
– System evaluation performed
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Planning and Modeling a Systems
Development Project
 Systems Operation, Support, and
Security
– A well-designed system must be secure,
reliable, maintainable, and scalable
– After several years of operation, systems need
extensive changes
– SDLC ends with system replacement
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Planning and Modeling a Systems
Development Project
 Joint Application Development and
Rapid Application Development
Methods and Models
– Joint application development (JAD)
– Rapid application development (RAD)
 Other Development Methods and
Models
– Rational Unified Process (RUP®)
– Microsoft Solutions Framework (MSF)
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Planning and Modeling a Systems
Development Project
 The Importance of Project Management
– Regardless of the development strategy,
people, tasks, timetables, and expenses must
be managed effectively
– Complex projects can involve dozens of
people, hundreds of tasks, and many
thousands of dollars
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Systems Development Guidelines
 Stick to a plan
 Involve the users throughout the
development process
 Listening is very important
 Use project management tools to
identify tasks and milestones
 Remain flexible
 Develop accurate cost and benefit
information
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Information Technology Department
 The information technology (IT)
department develops and maintains a
company’s information systems
 The IT group provides technical support
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Information Technology Department
 Application Development
– Team may include users, managers and IT
Staff members
 Systems Support and Security
– Deployment team
 User Support
– Help desk or information center (IC)
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Information Technology Department
 Database Administration
– Database design, management, security,
backup, and user access
 Network Administration
– Includes hardware and software maintenance,
support, and security
 Web Support
– Webmasters
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Information Technology Department
 Quality Assurance (QA)
– Reviews and tests all applications and systems
changes to verify specifications and software
quality standards
– Is a separate unit that reports directly to IT
management
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The Systems Analyst Position
 A systems analyst investigates,
analyzes, designs, develops, installs,
evaluates, and maintains a company’s
information systems
 On large projects, the analyst works as
a member of an IT department team
 Smaller companies often use
consultants to perform the work
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The Systems Analyst Position
 Responsibilities
– Translate business requirements into practical
IT projects to meet needs
 Required Skills and Background
– Solid communication skills and analytic ability
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The Systems Analyst Position
 Certification
 Career Opportunities
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Job titles
Company organization
Company size
Corporate culture
Salary, location, and future growth
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Chapter Summary
 IT is a combination of hardware, software, and
telecommunications systems that support
business
 The essential components of an information
system are hardware, software, data,
processes, and people
 Companies are production oriented, service
oriented, or a combination of the two
 Organization structure usually includes levels
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Chapter Summary
 Systems analyst use modeling, prototyping,
and CASE tools
 Various development methodologies exist
 Regardless of the development model, it is
important to use project management tools
necessary to manage people, tasks, timetables,
and expenses
 An IT department develops, maintains and
operates a company’s information systems
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Chapter Summary
 Systems analysts need a combination of
technical and business knowledge, analytical
ability, and communication
 Chapter 1 complete
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