Systems Analysis & Design ( Sixth Edition)

Chapter 1

Introduction to Systems Analysis and Design 1

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 2

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 3

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

4

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 5

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 6

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 7

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

8

Information System Components

System

A set of related components that produces specific results

Mission-critical system

A system that is

vital

company’s operations to a 9

Information System Components  Hardware Moore’s Law     Software System software Network operating system Application software Enterprise applications 10

Information System Components    Data The raw material that an information system transforms into useful information Tables Linking 11

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 12

Understanding The Business   Business Profile Business Models  Business models   Business process BPR (business process reengineering) 13

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 14

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 15

How Business Uses Information Systems  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 16

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 17

How Business Uses Information Systems   Enterprise computing systems Support company-wide operations and data management requirements Enterprise resource planning (ERP) 18

How Business Uses Information Systems  Transaction processing systems Efficient because they process a set of transaction-related commands as a group rather than individually 19

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 20

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 21

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 22

Information System Users and Their Needs

Organizational Model

 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  A typical organizational model, shown here, identifies the business functions and organizational levels 23

Information System Users and Their Needs     Top managers Middle Managers and Knowledge Workers Supervisors and Team Leaders Operational Employees 24

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 25

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 26

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 27

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) 28

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

29

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) 30

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

another object or information from 31

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) 32

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 33

The Systems Development Life Cycle 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

Waterfall Model Interactive Model

34

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

35

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

36

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

37

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 38

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 39

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 40

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: 41

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 42

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 43

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 44

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 45

The Systems Analyst Position      Certification  Professional credential Career Opportunities Job titles Company organization Company size Corporate culture Salary, location, and future growth 46

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 47

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 48

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?

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