1 The Impact of Information Technology The Role of Systems Analysis and Design –Systems Analysis and DesignSystems Analysis and Design Step-by-step process

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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

– 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– Internet-based application services – Outsourcing– Custom solutions– Enterprise-wide software strategies– How versus What

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Figure 1-5

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

Data consists of basic facts that are the system’s raw material

Figure 1-6

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Figure 1-7


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

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

Figure 1-8

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Hardware – Is the physical layer of the

information system– Moore’s Law


Figure 1-9For more information about Moore’s Law visit scsite.com/sad7e/more, locate Chapter 1 and then the Moore’s Law link.

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

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Data – Is the raw material that an

information system transforms into useful information

– Tables– Linking

Figure 1-10

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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 Process Modeling Business Profile Business Models

– Business model– Business process– Business process reengineering (BP

R)

Figure 1-11

Figure 1-12

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Understanding The Business

New Kinds of Companies– Production-oriented – Service-oriented– Internet-dependent– Dot-com (.com)– Brick-and-mortar

Figure 1-13

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Impact of the Internet

E-Commerce or I-Commerce B2C (Business-to-Consumer) B2B (Business-to-Business)

– EDI– Extensible markup language (XML)– Supplier relationship management (

SRM)

Figure 1-14For more information aboutE-commerce visit scsite.com/sad7e/more, locate Chapter 1 and then the Electronic commerce link.

For more information about XML visit scsite.com/sad7e/more, locate Chapter 1 and then the Extensible Markup Language link..

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Impact of the Internet

Web-Based System Development– WebSphere– .NET– Web services

Figure 1-15

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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)

Figure 1-16For more information about Enterprise Resource Planning visit scsite.com/sad7e/more, locate Chapter 1 and then the Enterprise Resource Planning link.

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Transaction processing systems– Efficient because they process a set

of transaction-related commands as a group rather than individually

Figure 1-17

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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

Figure 1-18

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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

Figure 1-29For more information about Knowledge Management systems visit scsite.com/sad7e/more, locate Chapter 1 and then the Knowledge Management systems link.

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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.

Figure 1-20

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Information System Users and Their Needs

Top managers– Strategic plans

Middle Managers and Knowledge Workers

Supervisors and Team Leaders Operational Employees

– Empowerment

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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– 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– Also called

computer-aided software engineering

– CASE tools

Figure 1-21

Figure 1-22For more information about CASE tools visit scsite.com/sad7e/more, locate Chapter 1 and then the CASE tools link.

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Systems Development Methods

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

The important thing is for a systems analyst to understand the various methods and the strengths and weaknesses of each approach

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Structured Analysis– Systems development life cycle (SD

LC)– Predictive approach– Uses a set of process models to

describe a system graphically– Process-centered technique

Figure 1-23

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Object-oriented Analysis– O-O analysis combines data &

processes into objects– Object is a member of a class– Objects possess properties– Methods change an object’s

properties– A message requests specific

behavior or information from another object

Figure 1-24

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Planning and Modeling a Systems Development Project

In addition to selecting a development method, system developers also must create a plan or model for the many tasks that will be required

Typically, the development team will use project management tools to help achieve the end result

Figure 1-25

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Comparison of Predictive and Adaptive Models– The SDLC usually is referred to as

the waterfall model– Interactive model– Adaptive or iterative approaches– Spiral model

Figure 1-26

Figure 1-27

Figure 1-28

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The SDLC Waterfall Model– 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

– However, adjacent phases usually interact

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The SDLC Waterfall Model– Usually includes five steps

• Systems planning• Systems analysis• Systems design• Systems implementation• Systems operation, support, and

security

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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 whose key part is a feasibility study

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Systems Analysis– Systems analysis phase– 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– Systems design phase– Identify all outputs, inputs, and

processes– Avoid misunderstanding through

manager and user involvement– End product is

system design specification

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Systems Implementation– Systems implementation phase– 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

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Systems Operation, Support, and Security– Systems Operation, Support, and S

ecurity phase– A well-designed system must be

secure, reliable, maintainable, and scalable

– After several years of operation, systems need extensive changes

– SDLC ends with system replacement

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Adaptive Methods and Models– Attempt to develop a system

incrementally, by building a series of prototypes and constantly adjusting them to user requirements

– Extreme Programming (XP)– Analysts should recognize that

these approaches have advantages and disadvantages

Figure 1-29 Figure 1-30

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Joint Application Development and Rapid Application Development Methods and Models– Joint application development (JAD)– Rapid application development (RA

D)

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Other Development Methods and Models– Rational Unified Process (RUP®)– Microsoft Solutions Framework

(MSF)

Figure 1-31For more information about Microsoft Solutions Framework visit scsite.com/sad7e/more, locate Chapter 1 and then the Microsoft Solutions Framework link.

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The Importance of Project Management– Regardless of the development

strategy, people, tasks, timetables, and expenses must be managed effectively

– Complex projects can involve dozens of people, hundreds of tasks, and many thousands of dollars

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Systems Development Guidelines

Stick to a plan Involve the users throughout the

development process Listening is very important Use project management tools to

identify tasks and milestones 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

Figure 1-33

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Application Development– Team may include users, managers

and IT Staff members Systems Support and Security

– Deployment team User Support

– Help desk or information center (IC)

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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

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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

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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

analytic ability

Figure 1-34

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Certification– Professional credential

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

Documents

1 The Impact of Information Technology The Role of Systems Analysis and Design –Systems Analysis and DesignSystems Analysis and Design Step-by-step process