chapter 1 introduction to systems analysis and design bisi 4230 summer ‘05

Chapter 1Introduction to Systems Analysis

and Design

BISI 4230

Summer ‘05

Chapter Objectives

• Discuss the impact of information technology on business

• Describe an information system and explain its components

• Use profiles and models to understand business functions and operations

• Understand the impact of the Internet on business

• Identify various types of information systems and explain who uses them

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

Introduction

• Companies use information as a weapon to:– increase productivity, – deliver quality products and services,– maintain customer loyalty, and – make sound decisions.

Figure 1-1

• Information technology can mean the difference between success and failure

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


• The Future of IT– Responsible for half of all productivity growth

and a third of all economic growth between 1995-1999

– Online population worldwide is expected to increase 60 percent between 2001-2004


• 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 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


• Responsibilities– Translate business requirements into practical

IT projects to meet needs

• Required Skills and Background– Solid communication skills and analytic ability

Figure 1-31


• Who develops Information Systems?– In-house applications– Software packages– Internet-based application services – Outsourcing– Custom solutions– Enterprise-wide software strategies

• Risk in launching new IS– How versus What

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

• Information systems have five key components: hardware, software, data, processes, and people

Figure 1-9

• Hardware – Is the physical layer of the information system

– Moore’s Law• Processing power doubles every 18 months



• Software– Programs (set of instructions) that control hardware– System software

• [Network] operating system• Utility programs• Device drivers• Security software

– Application software • Enterprise applications• Horizontal system• Vertical system


• Data – Is the raw material that an information system

transforms into useful information

Figure 1-11


• 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

Understanding The Business

What are the business operations?

• Business Process Modeling

• Business Profile– Business models

• Business process(es)

– BPR (business process reengineering)

Figure 1-12

Understanding The Business

New Kinds of Companies– Companies are classified based on their main

activities:

• Traditional companies– Production-oriented – Service-oriented

• Internet-dependent– Brick-and-mortar vs.

pure-play/click-through/Dot-com(.com)

Figure 1-14

Impact of the Internet

• E-Commerce (I-Commerce)– B2C (Business-to-Consumer)– B2B (Business-to-Business)

• EDI

• Web-Based System Development– WebSphere– .NET– J2EE

How Business Uses InformationSystems

• In past, IT managers divided systems into categories based on the user group the system served– Office systems (admin staff)– Operational systems (operational personnel)– Decision support systems (middle m’gers)– Executive information systems (top m’gers)

How Business Uses Information

Systems• Today, it makes more sense to identify a

system by its functions & features, rather than by users – Enterprise computing systems– Transaction processing systems– Business support systems– Knowledge management systems– User productivity systems

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.

Figure 1-21

Systems Development Tools and Techniques

• Systems analysts must know how to use a variety of techniques such as – [business operations],– modeling, – prototyping, and – computer-aided systems engineering

tools to plan, design, and implement IS• Systems analysts work with these tools in

a team environment


• Modeling– Model = a graphical of a concept or process

• Business/Requirements model• Data model• Object model• Network model• Process model


• Prototyping– Early working version of an information

system [tests system concepts]– Speeds up the development process

significantly– Important decisions might be made too early,

before business or IT issues are thoroughly understood


• Computer-Aided Systems/Software Engineering (CASE) Tools– Framework for systems development and

support a wide variety of design methodologies

– CASE tools

Figure 1-24

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.


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

system graphically

– Systems development life cycle (SDLC)• Series of phases in structures analysis• Plan, Analyze, Design, Implement, Support

Figure 1-25


• Object-oriented (O-O) analysis– O-O analysis combines data & processes into

objects– Objects possess properties and methods– Methods change an object’s properties– Messages request specific behavior or

information from another object

Figure 1-26


• Joint Application Development and Rapid Application Development– JAD – Team based fact finding– RAD – compressed version of the entire

process

The Systems Development Life Cycle

• It includes the following steps:– Systems planning– Systems analysis– Systems design– Systems implementation– Systems operation and support


• 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

Figure 1-28

Figure 1-29


• 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


• 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


• 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 system design specification


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

and support the system– System evaluation performed


• Systems Operation and Support– New system supports operations– Maintenance changes correct errors or meet

requirements– Enhancements increase system capability– After several years of operation, systems

need extensive changes – SDLC ends with system replacement

Information Technology Department

• The information technology (IT) department develops and maintains a company’s information systems.

• The IT group provides technical support – includes six main functions: application

development, systems support, user support, database administration, network administration, and Web support

Figure 1-30


• Application Development– Team may include users, managers and IT

Staff members

• Systems Support– Provides hardware and software support

• User Support– Provides users with technical information,

training, and productivity support


• 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


• Certification– Professional credential

• Career Opportunities– Job titles– Company organization– Company size– Corporate culture– Salary, location, and future growth

Test Yourself

1. In order to best support user’s IT needs, IT professionals need to understand the company’s business operations. What process might a system analyst use to accomplish this?

Test Yourself

1. In order to best support user’s IT needs, IT professionals need to understand the company’s business operations. What process might a system analyst use to accomplish this? – Business process modeling is used to

represent a company’s operations and information needs

Test Yourself

2. What are the five key components of information systems?

Test Yourself

2. What are the five key components of information systems?

Hardware

Software

Data

Processes

People

Test Yourself

3. How are business information systems identified?

Test Yourself

3. How are business information systems identified?

– Functions and features

Test Yourself

4. T/F: An enterprise computing system is highly specialized and targeted for a company’s top executives.

Test Yourself

4. T/F: An enterprise computing system is highly specialized and targeted for a company’s top executives.

False. Enterprise computing systems support company-wide data management requirements

Test Yourself

5. Top management is typically responsible for ________ planning, while middle management focuses on __________ planning.

Test Yourself

5. Top management is typically responsible for strategic planning, while middle management focuses on tactical planning.

Test Yourself

6. CASE tools are:

a) an object oriented methodology

b) techniques or tools to help plan and design information systems

c) team-based fact finding techniques

Test Yourself

7. Objects, classes, and methods are all terms used in structured/object oriented methodologies

Test Yourself

7. Objects, classes, and methods are all terms used in structured/ object oriented methodologies

Test Yourself

8. What are the phases of the systems development life cycle?

Test Yourself

8. What are the phases of the systems development life cycle?

– Systems planning– Systems analysis– Systems design– Systems implementation– Systems operation and support

Test Yourself

9. List at least three of the six functions of a typical IT department

Test Yourself

9. List at least three of the six functions of a typical IT department1. Application development

2. Systems support

3. User support

4. Database administration

5. Network administration

6. Web support

Test Yourself

10. T/F Certification is a professional credential that is valued by little (if any) companies.

Test Yourself

10. T/F Certification is a professional credential that is valued by little (if any) companies.

False

End Chapter 1

chapter 1 introduction to systems analysis and design bisi 4230 summer ‘05

Documents

companys information

systems analysts

software products

structured analysis

designsystems analysis

productivity growth

set of related components

needsrequired skills