Systems Analysis & Design Sixth Edition Chapter 1.

Systems Analysis & Design

Sixth 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

● 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 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 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

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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

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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

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● Hardware – Moore’s Law

● Software– System software– Network operating system– Application software – Enterprise applications– Horizontal system– Vertical system


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● Data – Is the raw material that an information

system transforms into useful information– Tables– Linking

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● 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 their 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 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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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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● Transaction processing systems– Efficient because

they process a set of transaction-related commands as a group rather than individually

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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

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● 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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● 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 model in order to recognize who is responsible for specific processes and decisions and to be aware of what information is required by whom

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Information System Users and Their Needs

● Top managers● Middle Managers and Knowledge

Workers ● Supervisors and Team Leaders ● Operational Employees ● Strategic plans

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Systems Development Tools and Techniques

● 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

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● Modeling– Used to describe and simplify an

information system:– Business model– Requirements model– Data model– Object model– Network model– Process model

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● 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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● Computer-Aided Systems Engineering (CASE) Tools– Framework for systems development and

support a wide variety of design methodologies

– CASE tools

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Systems Development Methods

● Structured analysis and object-oriented analysis are both popular methodologies for developing computer-based information systems

● A systems analyst should understand the alternative methodologies and their individual strengths and weaknesses

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● Structured Analysis– Uses a set of process models to describe a

system graphically– Systems development life cycle (SDLC)

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● 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 properties– Methods change an object’s properties– Messages request specific behavior or

information from another object

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● 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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● Traditionally 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

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● Systems planning– Purpose is to identify the nature and scope

of the business opportunity or problem– Systems request – begins the process &

describes problems or desired changes– Systems planning includes preliminary

investigation whose key part is a feasibility study

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● 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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● 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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● Systems Implementation– New system is constructed– Write, test, & document programs– File conversion occurs– Users, managers, IT staff trained to

operate and support the system– Systems evaluation performed

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● 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

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● 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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● 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 and

presence– 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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● Responsibilities– Translate business requirements into

practical IT projects to meet needs

● Required Skills and Background– Solid communication skills and analytical

ability

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● 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

● Chapter 1 Complete

Systems Analysis & Design Sixth Edition Chapter 1.

Documents

useful information tables

failure slide

business strategies

business functions

internet dependent slide

business strategy

systems analysis design

design systems analysis