systems analysis & design (sixth edition) 1 chapter 1 introduction to systems analysis and...
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Systems Analysis & Design(Sixth Edition)
Chapter 1
Introduction to
Systems Analysis and Design
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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
Use profiles and models to understand 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 systems development tools, including modeling, prototyping, and CASE tools
Distinguish between structured analysis and object-oriented methodology
Describe the systems development life cycle 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
Accounted for almost 30 percent of economic growth in 2003
Online population worldwide increased 106 percent between 2000-2004
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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 high-quality
information systems
Information System Combines information technology, people, and data to
support business requirements
Systems Analyst Plan, develop, and maintain information systems
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The Impact of Information Technology
Who Develops Information Systems? In-house applications Software packages (outside vendors) Internet-based application services Outsourcing (outside development) Custom solutions (IT consultants) Enterprise-wide software strategies How versus What
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Information System Components
System
A set of related components that produces specific results
Mission-critical system A system that is vital to a company’s operations
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Hardware Moore’s Law
Software System software Network operating system Application software Enterprise applications
Information System Components
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Information System Components
Data The raw material that an information system
transforms into useful information 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 Profile Business Models
Business models Business process BPR (business process reengineering)
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Understanding The Business
New Kinds of Companies Companies are classified
based on main activities: Product-oriented Service-oriented Brick-and-mortar Dot-com (.com) or Internet-
dependent
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Impact of the Internet
E-Commerce (I-Commerce) B2C (Business-to-Consumer) B2B (Business-to-Business)
EDI, XML, HTML Web-Based Development
WebSphere, .NET Web services
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How Business Uses InformationSystems
In the past, IT managers divided systems into categories based on the user group that the system served:
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
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 Enterprise resource planning (ERP)
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How Business Uses Information Systems
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 analysis
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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
A systems analyst must understand the company’s organizational modelorganizational model in order to recognize who is responsible for specific processes and decisions and to be aware of what information is required by whom
A typical organizational model, shown here, identifies the business functions and organizational levels
Organizational ModelOrganizational Model
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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
Systems analysts must know how to use a variety of techniques:
Modeling Prototyping CASE (computer-aided systems engineering) tools
in order to plan, design and implement the systems Systems analysts work with these
tools/techniques in a team environment
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Systems Development Tools and Techniques
Modeling is used to describe and simplify an information system:
Business model AKA Requirements model Data model Object model Network model Process model
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Systems Development Tools and Techniques
Prototyping Utilizes a Prototype Can speed up development significantly Disadvantage: Important decisions might be
made too early, before business or IT issues are thoroughly understood
Advantage: Can be an extremely valuable tool, based on careful fact-finding/modeling
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Systems Development Tools and Techniques
Computer-Aided Systems Engineering (CASE) Tools Framework for systems development and support
a wide variety of design methodologies CASE tools
http://www.agilemodeling.com/essays/simpleTools.htm
http://www.cs.queensu.ca/Software-Engineering/toolcat.html
(websites that list CASE tools)
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Systems Development Methods
Structured analysis* and Object-oriented analysis are both popular methodologies for developing information systems
In addition to the above methodologies, a systems analyst should understand alternatives
JAD RAD Microsoft Solutions Framework (MSF) Homegrown / Consultant / Software Company
* Used most often
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Systems Development Methods
Structured Analysis Systems development life cycle (SDLC) Uses a set of process models to describe a
system graphically
http://www.idinews.com/story.html
(Website with information on structured analysis and OO analysis)
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Systems Development Methods
Object-oriented (O-O) analysis O-O analysis combines data & processes into objects Object is a member of a class Class is a collection of similar objects Objects possess characteristics called properties Methods change an object’s properties Messages request specific behavior or information from
another object
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Systems Development Methods
Joint Application Development and Rapid Application Development
JAD – Team based fact finding RAD – compressed version of the entire process
Other development methodologies Microsoft Solutions Framework (MSF)
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The Systems Development Life Cycle
SDLC used to plan and manage the systems development process
It includes the following steps: Systems planning phase Systems analysis phase Systems design phase Systems implementation phase Systems operation, support, and security phase Deliverable or end product
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The Systems Development Life CycleTraditionally pictured as a waterfall model, but is also presented as an interactive model depicting real world practice and the constant dialog among users, managers, and systems developers
Interactive ModelInteractive ModelWaterfall ModelWaterfall Model
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The Systems Development Life Cycle
Systems planning Systems request – begins the process &
describes problems or desired changes Purpose is to identify the nature and scope of
the business opportunity or problem Systems planning includes preliminary
investigation whose key part is a feasibility study
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The Systems Development Life Cycle
Systems Analysis Purpose is to build a logical model of the new
system First step is requirements modeling, where
you investigate business processes and document what the new system must do
End product is the system requirements document
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The Systems Development Life Cycle
Systems Design Purpose is to create a blueprint that will satisfy
all documented requirements Identify all outputs, inputs, and processes Avoid misunderstanding through manager and
user involvement End product is systems design specification
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The Systems Development Life Cycle
Systems Implementation New system is constructed Write, test, & document programs (CODING) File conversion occurs
(Whether a purchased package or not configure s/w, etc.)
Users, managers, IT staff trained to operate and support the system
Systems evaluation performed
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The Systems Development Life Cycle
Systems operation, support, and security New system supports operations Maintenance changes correct errors or meet
requirements Enhancements increase system capability Well-designed system will be secure, reliable,
maintainable, and scalable SDLC ends with system replacement
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Systems Development Guidelines
Planning Involve users throughout the development
process Listening is very important Create a time table with major milestones Identify interim checkpoints 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 which includes 6 main functions listed below:
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Information Technology Department
Application Development Team may include users, managers and IT staff
members
Systems Support and Security Provides hardware and software support
User Support Provides users with technical information, training,
and productivity support Help desk
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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 Design and construction of Web pages Important for e-commerce Webmaster
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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 Good analytical ability Technical knowledge is helpful Understanding of business and processes
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The Systems Analyst Position
Certification Professional credential
Career Opportunities 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 and software that support business
The essential components of an information system are hardware, software, data, processes, and people
Companies are product-oriented, service-oriented, or a combination of the two
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Chapter Summary
Organization structure usually includes levels. Each level has different responsibilities and information needs
Systems analysts use modeling, prototyping, and CASE tools. Modeling produces a graphical representation of the process, prototyping involves creation of an early working model, and CASE tools assist in various systems development tasks
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Chapter Summary
The Systems Development Life Cycle (SDLC) consists of five phases: systems planning, systems analysis, systems design, systems implementation, and systems operation, support, and security
Systems analysts need a combination of technical and business knowledge, analytical ability, and communication skills
Any questions?