CHAPTER 1 I NTRODUCTION TO SYSTEM ANALYSIS AND DESIGN.

CHAPTER 1

INTRODUCTION TO SYSTEM ANALYSIS AND DESIGN

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

5

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


6

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


7

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


8

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

9

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


10

Information is data that has been transformed into output that is valuable to users

Information systems have FIVE key components:


11

Hardware Is the physical layer of the information

system Moore’s Law

Figure 1-9


12

Software System software Application software Enterprise applications Horizontal system Vertical system Legacy systems


13

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


14

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

15

Business Process Modeling A process used by systems analysts to

represent a company's operations and information needs


16

Business Profile defines a company's overall functions,

processes, organization, products, services, customers, suppliers, competitors, constraints, and future direction


17

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


18

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

21

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

22

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


23

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


24

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


25

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


26

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


27

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


Information System Users and Their Needs

28

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

29

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


Modeling Business model Requirements model Data model Object model Network model Process model


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


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

34

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


35

It is not unusual for system developers to mix and match methods

People, tasks, timetables, and costs must be managed efficiently

Project management


36

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


37

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


38

Structured Analysis The SDLC model usually includes five steps

Systems planning Systems analysis Systems design Systems implementation Systems support and security


39

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


40

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


41

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


42

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


43

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


44

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


45

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


46

Agile Methods Are the newest development Emphasizes continuous feedback Iterative development Agile community has published the Agile

Manifesto Spiral model


47

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


48

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)


49

Other Development Methods Might encounter other systems

development techniques Rational Unified Process (RUP®) Microsoft Solutions Framework (MSF)

Systems Development Guidelines

50

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

51

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


52

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)


53

Database Administration Database design, management, security,

backup, and user access Network Administration

Includes hardware and software maintenance, support, and security

Web Support Webmasters


54

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

55

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


56

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.


57

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

End of Chapter 1

Continue Next Chapter 2

CHAPTER 1 I NTRODUCTION TO SYSTEM ANALYSIS AND DESIGN.

Documents

information needsunderstanding

system analysis

systems analysts

business functions

role of systems analysis

business strategy

business profiledefines

business strategies