CHAPTER 1 I NTRODUCTION TO SYSTEM ANALYSIS AND DESIGN.
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Chapter Objectives 2
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
Chapter Objectives3
Identify various types of information systems and explain who uses them
Distinguish between structured analysis, object-oriented analysis, and agile methods
Compare the traditional waterfall model with agile methods and models
Discuss the role of the information technology department and the systems analysts who work there
Introduction4
Companies use information: to sustain and survive in a business
environment as a weapon in the battle to increase
productivity, deliver quality products and services, maintain customer loyalty, and make sound decisions.
IT can mean the difference between success and failureFigure 1-1
The Impact of Information Technology
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Information Technology (IT) 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
The Impact of Information Technology
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The Future of IT Will see robust growth for at least a decade The greatest need will be for systems
analysts, network administrators, data communications analysts, and software engineers
The Impact of Information Technology
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The Role of Systems Analysis and Design Systems Analysis and Design
Step-by-step process for developing high-quality information systems
Systems Analyst Plan, develop, and maintain information
systems
The Impact of Information Technology
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Who develops Information Systems? In-house applications Software packages Internet-based application services Outsourcing Custom solutions Enterprise-wide software strategies How versus What
Information System Components
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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
Information System Components
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Information is data that has been transformed into output that is valuable to users
Information systems have FIVE key components:
Information System Components
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Hardware Is the physical layer of the information
system Moore’s Law
Figure 1-9
Information System Components
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Software System software Application software Enterprise applications Horizontal system Vertical system Legacy systems
Information System Components
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Data Is the raw material that an information
system transforms into useful information Tables store data By linking the tables, the system can
extract specific information
Information System Components
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Processes Describe the tasks and business functions
that users, managers, and IT staff members perform to achieve specific results
People Stakeholders Users, or end users
Understanding The Business
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Business Process Modeling A process used by systems analysts to
represent a company's operations and information needs
Understanding The Business
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Business Profile defines a company's overall functions,
processes, organization, products, services, customers, suppliers, competitors, constraints, and future direction
Understanding The Business
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Business Models Business model
graphically represents business functions that consist of business processes, such as sales, accounting, and purchasing
Business process describes specific events, tasks, and desired
results Business process reengineering (BPR)
An attempt by companies to simplify operations or reduce costs
Understanding The Business
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New Kinds of Companies Production-oriented Service-oriented Internet-dependent Dot-com (.com) Brick-and-mortar
Impact of the Internet19
E-Commerce or I-Commerce B2C (Business-to-Consumer) B2B (Business-to-Business)
EDI Extensible markup language (XML) Supplier relationship management (SRM)
Impact of the Internet20
Web-Based System Development WebSphere: IBM .NET: Microsoft PHP Zend Framework: Zend Web services Internet-based systems involve various
hardware and software designs Career opportunities will expand
How Business Uses Information Systems
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In past, IT managers divided systems into categories based on the user group the system served Office systems Operational systems Decision support systems Executive information systems
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Today, it makes more sense to identify a system by its functions and features, rather than by its users Enterprise computing systems Transaction processing systems Business support systems Knowledge management systems User productivity systems
How Business Uses Information Systems
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Enterprise computing systems Support company-wide operations and data
management requirements Enterprise resource planning (ERP) Many hardware and software vendors
target the enterprise computing market
How Business Uses Information Systems
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Transaction processing systems Involve large amounts of data and are
mission-critical systems Efficient because they process a set of
transaction-related commands as a group rather than individually
How Business Uses Information Systems
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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
How Business Uses Information Systems
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Knowledge management systems Called expert systems Simulate human reasoning by combining a
knowledge base and inference rules Many knowledge management systems use
technique called fuzzy logic
How Business Uses Information Systems
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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
How Business Uses Information Systems
Information System Users and Their Needs
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A systems analyst must understand the company’s organizational model to recognize who is responsible for specific processes and decisions and to be aware of what information is required by whom
Information System Users and Their Needs
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Top managers Strategic plans
Middle Managers and Knowledge Workers
Supervisors and Team Leaders Operational Employees
Empowerment
Systems Development Tools30
Systems analysts must know how to use a variety of techniques such as modeling, prototyping, and computer-aided systems engineering tools to plan, design, and implement information systems.
Systems analysts work with these tools in a team environment
Systems Development Tools31
Modeling Business model Requirements model Data model Object model Network model Process model
Systems Development Tools32
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
Systems Development Tools33
Computer-Aided Systems Engineering (CASE) Tools Also called computer-aided software
engineering CASE tools Can generate program code, which speeds
the implementation process
Overview of Systems Development Methods
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The most popular alternatives are structured analysis, which is a traditional method that still is widely used, and object-oriented analysis (O-O), which is a newer approach that many analysts prefer, and agile methods, also called adaptive methods
Understand the various methods and the strengths and weaknesses of each approach
Overview of Systems Development Methods
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It is not unusual for system developers to mix and match methods
People, tasks, timetables, and costs must be managed efficiently
Project management
Overview of Systems Development Methods
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Structured Analysis Systems development life cycle (SDLC) Predictive approach Uses a set of process models to describe a
system graphically Process-centered technique Waterfall model
Overview of Systems Development Methods
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Structured Analysis Deliverable or end product 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
Adjacent phases usually interact
Overview of Systems Development Methods
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Structured Analysis The SDLC model usually includes five steps
Systems planning Systems analysis Systems design Systems implementation Systems support and security
Overview of Systems Development Methods
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Structured Analysis Systems Planning
Systems planning phase Systems request – begins the process &
describes problems or desired changes Purpose of this phase is to perform a
preliminary investigation Key part of preliminary investigation is a
feasibility study
Overview of Systems Development Methods
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Structured Analysis Systems Analysis
Systems analysis phase First step is requirements modeling, where you
investigate business processes and document what the new system must do to satisfy users
Deliverable is the System requirements document
Overview of Systems Development Methods
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Structured Analysis Systems Design
Systems design phase Identify necessary outputs, inputs, and
processes Design internal and external controls Determine the application architecture Deliverable is system design specification Management and user involvement is critical
Overview of Systems Development Methods
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Structured Analysis Systems Implementation
Systems implementation phase New system is constructed Programs are written, tested, and documented,
and the system is installed Includes an assessment, called a system
evaluation
Overview of Systems Development Methods
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Structured Analysis Systems Support and Security
Systems Operation, Support, and Security phase
A well-designed system must be secure, reliable, maintainable, and scalable
Most information systems need to be updated significantly or replaced after several years of operation
Overview of Systems Development Methods
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Object-Oriented Analysis Combines data & processes that act on the
data into things called objects Object is a member of a class Objects possess properties Methods change an object’s properties
Overview of Systems Development Methods
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Object-Oriented Analysis A message requests specific behavior or
information from another object Usually follow a series of analysis and
design phases that are similar to the SDLC Interactive model
Overview of Systems Development Methods
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Agile Methods Are the newest development Emphasizes continuous feedback Iterative development Agile community has published the Agile
Manifesto Spiral model
Overview of Systems Development Methods
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Agile Methods Agile process determines the end result Other adaptive variations and related
methods exist Two examples are Scrum and Extreme
Programming (XP) Analysts should understand the pros and
cons of any approach before selecting a development method
Overview of Systems Development Methods
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Other Development Methods IT departments have long sought to avoid
systems that were developed without sufficient input from users
Joint application development (JAD) Rapid application development (RAD)
Overview of Systems Development Methods
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Other Development Methods Might encounter other systems
development techniques Rational Unified Process (RUP®) Microsoft Solutions Framework (MSF)
Systems Development Guidelines
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Develop a project plan Involve users and listen carefully to them Use project management tools to
identify tasks and milestones Develop accurate cost and benefit
information Remain flexible
Information Technology Department
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The information technology (IT) department develops and maintains a company’s information systems.
The IT group provides technical support These functions overlap considerably
and often have different names in different companies
Information Technology Department
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Application Development Teams consisting of users, managers and IT
Staff members Systems Support and Security
Deployment team User Support
Help desk or information center (IC)
Information Technology Department
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Database Administration Database design, management, security,
backup, and user access Network Administration
Includes hardware and software maintenance, support, and security
Web Support Webmasters
Information Technology Department
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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
The Systems Analyst Position
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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 systems analysis work on an as-needed basis
The Systems Analyst Position
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Responsibilities Translate business requirements into IT
projects Required Skills and Background
Solid technical knowledge, strong oral and written communication skills and analytic ability, and an understanding of business operations and processes.
The Systems Analyst Position
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Certification Important credential
Career Opportunities Job titles Company organization Company size Corporate culture Salary, location, and future growth
Chapter Summary58
IT refers to the combination of hardware and software resources that companies use to manage, access, communicate, and share information
The essential components of an information system are hardware, software, data, processes, and people
Most companies offer a mix of products, technical and financial services, consulting, and customer support
Chapter Summary59
Information systems are identified as enterprise computing systems, transactional processing or operational systems, business support systems, knowledge management systems, or user productivity systems
Organization structure includes top managers, middle managers and knowledge workers, supervisors and team leaders
Chapter Summary60
Systems analysts use modeling, prototyping, and computer aided systems engineering (CASE) tools
Three popular system development approaches are structured analysis, object-oriented analysis (O-O), and agile methods, also called adaptive methods
Chapter Summary61
Regardless of the development strategy, people, tasks, timetables, and cost must be managed effectively using project management tools
The IT department develops, maintains and operates a company’s information systems
Chapter Summary62
Systems analysts need a combination of technical and business knowledge, analytical ability, and communication skills
Systems analysts need to consider salary, location, and future growth potential when making a career decision
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