introduction to system analysis and development the value of analysis and design components of is...

Introduction to System Analysis and Development

The Value of Analysis and DesignComponents of ISEthical Issues

Dr Manolya KavakliSenior Lecturer Department of Computer ScienceMacquarie University

Read: Ch 1 [Shelly]

Chapter Objectives

• Discuss the impact of information technology on business strategy and success

• Define an information system and describe its components

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

Chapter Objectives

• Explain modeling, prototyping, and CASE tools• Distinguish between structured analysis and

object-oriented analysis• Compare the systems development life cycle

waterfall model to adaptive models• Discuss the role of the information technology

department and the systems analysts who work there

• Discuss Ethical Issues

Introduction• Why do companies use

information?• 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.

Definition of Information Technology• What is IT?

• Information Technology – Combination of hardware and software products and services that

companies use.

• What do companies do with the information? – manage, – access, – communicate, and – share information.– A vital asset that must be used

• effectively, • updated constantly, and • safeguarded carefully.

The Impact of IT• Who uses Internet most in the world?• a)Asia b)America c)Australia d)Europe e)Africa• Internet Usage (% of population)

– Asia: 9.9% and Middle East: 9.6%– North America: 68.6%– Australia: 52.6%– Europe: 36.1%– Africa: 2.6%

• The Future of IT– IT sector accounts for almost 30 percent of America’s economic

growth, and the wage gaps between IT workers and all other workers will continue to widen

– Global online population skyrocketed between 2000 and 2007

The Impact of IT• What is The Role of Systems Analysis and Design?

– Systems Analysis and Design:• A Step-by-step process for developing high-quality information systems.

• What does an Information System combine?• IT,• People, and• Data to support business requirements.

• Who do we need to build an Information System?• Systems Analyst:

– Plan, develop, and maintain information systems.

The Impact of IT• What type of methods are used to develop Information

Systems?• A company develops its own ISs using

– In-house applications– Software packages from outside vendors– Internet-based application services – Outsourcing– Custom solutions from IT consultants– Enterprise-wide software strategies

• Launching a new IS is risky.• How versus What

– Outline What the system is supposed to do– Before How it will be developed.

Introduction to Information System Components

• A system:• a set of related components that

produces specific results• A mission-critical system:• one that is vital to a company’s

operations• Data: • consists of basic facts that are the

system’s raw material• Information:• Data that has been transformed into

output that is valuable to users.

• Hardware – Consists of everything in the physical layer of IS

• E.g., servers, workstations, networks, telecomm. equipment, scanners.

• Software– Refers to the programs that control the hardware and produce the

desired information or results.Types of Software: – System software manages hardware components

• Operating system, security software, device drivers, etc.

– Application software supports day to day business functions• order processing systems, payroll systems, company communications

networks• spreadsheets, word processors, database systems

Information System Components

Types of Application software

– Enterprise applications • (company wide applications such as order processing systems,

payroll systems, company communications networks)

• (on a smaller scale, spreadsheets, word processors, database systems)

– Horizontal systems • (inventory or payroll application) that can be adapted for use in

many different types of companies)

– Vertical systems • designed to meet the unique requirements of a specific business

– Legacy systems• new systems to interface with older systems

Information System Components

• Data – Tables

– Linking

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

Understanding The Business• Business Process Modeling

– represents a company’s operations and information needs and requires

– Business Profile• Desribes a company’s overall functions, processes, products,

services, etc.

– Business Models• Graphical representation of business processes

– Airline reservation, selling a ticket

• To simplify operations we use

• Business process reengineering

(BPR)

Understanding The Business

• Kinds of Companies– Product-oriented– Service-oriented– Internet-dependent

• Dot-com (.com) companies such as Google, Yahoo, e-Bay

– Brick-and-mortar companies such as K-Mart, Target, etc.

Impact of the Internet• E-Commerce or I-Commerce

– Internet based commerce– Includes two main sectors:

• B2C (Business-to-Consumer)– Consumers go online and purchase products and services

• eBay.com using a traditional auction concept

• B2B (Business-to-Business)– Important to reduce costs – Allows smaller suppliers to contact large customers

• Started with EDI –Electronic Data Interchange (company to company data sharing arrangements)

• Extensible markup language (XML) enabled company to company traffic using Web based communication.

• Supplier relationship management (SRM) is a form of interaction to submit specifications for business transactions.

How Business Uses InformationSystems

• In past, IT managers divided systems into categories based on the user group the system served– Office systems

• (for admin staff)

– Operational systems • (for operational personnel)

– Decision support systems • (for middle managers)

– Executive information systems • (for top managers)

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

How Business Uses Information Systems

• Enterprise computing systems– Support company-wide operations

and data management requirements• K-Mart’s inventory control system• Singapore Airlines’ reservation system

• Transaction processing systems– Efficient because they process a set

of transaction-related commands as a group rather than individually• Customer order processing• Warranty claim processing

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) to track physical objects using tags

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

• User productivity systems– Technology that improves productivity

• Email, voice mail, fax, video conferencing, internet.• Groupware enables users to share data, collaborate, and work

in teams.

How Business Uses Information Systems today

• Information systems integration– Most large companies require systems that combine

transaction processing, business support, knowledge management, and user productivity features.

– Warranty claim • into a transaction processing system,

• updates a knowledge management system to track product problems, and

• a quality control system with decision support capabilities.

IS Users and Their Needs• Top managers

– Strategic plans

• Middle Managers and Knowledge Workers– Direction, resources,

performance feedback

• Supervisors and Team Leaders – Operational and day-to

day functions

• Operational Employees– Use TP systems and

perform jobs

Systems Development Tools and Techniques• Modeling

– Produces a graphical representation of a concept or process that system developers can analyze, test, and modify.

– Business model / Requirements model• Describes the information that a system must provide

– Data model• Describes data structures and design

– Object model• Describes objects, which combine data and processes

– Network model• Describes the design and protocols of telecommunication links

– Process model• Describes the logic that programmers use to write code modules

Systems Development Tools and Techniques

• Prototyping tests system concepts– Prototype:

• Early working version of an IS.

– Advantage: Speeds up the development process significantly

– Disadvantage: Important decisions might be made too early, before business or IT issues are thoroughly understood

– Can be an extremely valuable tool.

Systems Development Tools and Techniques

• Computer-Aided Systems Engineering (CASE) Tools– Also called computer-aided software engineering

– A technique that uses powerful software called CASE tools to help system analysts develop and maintain ISs.

– Microsoft Project

– Microsoft Visio

Systems Development Methods

• Structured Analysis– Uses a series of phases called Systems development life

cycle (SDLC)

– To plan, analyze, design, implement and support an IS.

– Predictive approach

– Uses a set of process models to describe a system graphically

– Process-centered technique

Systems Development Methods

• Object-oriented Analysis– O-O analysis combines data & processes into objects

– Object (E.g, student/instructor/customer/order) is a member of a class (E.g., person)

– Objects possess properties (E.g., address/status)

– Methods change an object’s properties

– A message requests specific behavior or information from another object

– Visual Basic, Java, C++

Planning and Modeling a Systems Development Project

• O-O methods (interactive model) tend to be less sequential and more interactive compared to SDLC (waterfall model) which is more predictive. There are also adaptive/iterative approaches (using a spiral model).

• 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

• Adaptive approach using a spiral model– A set of prototypes evolves into final product

Planning and Modeling a Systems Development Project

Planning and Modeling a Systems Development Project

• Structured analysis uses The SDLC (Waterfall Model)– The result of each phase is called a deliverable or end

product which flows sequentially.– Disadvantage: 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

Planning and Modeling a Systems Development Project

• The SDLC Waterfall Model– Usually includes five steps

• Systems planning

• Systems analysis

• Systems design

• Systems implementation

• Systems operation,

support, and security

Planning and Modeling a Systems Development Project

• Systems planning– Systems request

– Purpose of this phase is to perform a preliminary investigation whose key part is a feasibility study

• Systems Analysis– First step is requirements modeling

– End product is the System requirements document

Planning and Modeling a Systems Development Project

• Systems Design– Identify all outputs, inputs, and processes– End product is system design specification

• Systems Implementation– New system is constructed– Users, managers, IT staff trained to operate

and support the system– System evaluation performed

Planning and Modeling a Systems Development Project

• Systems Operation, Support, and Security– 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

Planning and Modeling a Systems Development Project

• 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)• Interactive process between developers and users

– Analysts should recognize that these approaches have advantages and disadvantages

Planning and Modeling a Systems Development Project

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

• Team-based fact finding in one phase

– Rapid application development (RAD)• Team-based approach on the entire process

• Other Development Methods and Models– Rational Unified Process (RUP®)

• Iterative process for managing software development projects

– Microsoft Solutions Framework (MSF)• Similar to the SDLC but documents the experience of its own software

development teams• http://www.youtube.com/watch?v=vRioQNowpkI&feature=related

Planning and Modeling a Systems Development Project

• 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

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

Information Technology Department

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

• The IT group provides technical support

Information Technology Department

• 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)

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– Webmasters

Information Technology Department

• 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

• 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

The Systems Analyst Position

• Responsibilities– Translate business requirements into practical IT

projects to meet needs

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

– http://www.youtube.com/watch?v=sCFtBCbMOgY&feature=fvw

The Systems Analyst Position

• Certification– Cisco, Microsoft, ITIL

• Career Opportunities– Job titles

– Company organization

– Company size

– Corporate culture

– Salary, location, and future growth

Ethics

• Ethical behaviour could be viewed as – decent, fair, good, honest or moral behaviour

• Ethical standards:– framed by the society in which you choose to work

• Professional bodies – usually have a code of ethics and – will expel members who fail to uphold it.

• The pressures on many businesses can result in legal but not ethical behaviour – – however the advantage gained is usually short-lived

• Good ethics usually means good business.

The Ten Commandments of Computer Ethics

1. Thou shalt not use a computer to harm other people. 2. Thou shalt not interfere with other people’s computer

work. 3. Thou shalt not snoop around in other people’s computer

files. 4. Thou shalt not use a computer to steal.5. Thou shalt not use a computer to bear false witness. 6. Thou shalt not copy or use proprietary software for

which you have not paid.

The Ten Commandments of Computer Ethics

7.Thou shalt not use other people’s computer resources without authorization or proper compensation.

8. Thou shalt not appropriate other people’s intellectual output.

9. Thou shalt think about the social consequences of the program you are writing or the system you are designing.

10. Thou shalt always use a computer in ways that insure consideration and respect for your fellow human

The British Computer Society Code Of Conduct

• The BCS Code of Conduct is used here as an example:

• Members shall carry out work with due care and diligence in accordance with the requirements of the employer or client

• and shall, if their professional judgment is overruled, indicate the likely consequences.

• Members shall endeavour to complete work undertaken on time and to budget and shall advise their employer or client as soon as practicable if any overrun is foreseen.

Code Of Conduct

• Members shall not offer or provide, or receive in return, inducement for the introduction of business from a client unless there is full prior disclosure of the facts to the client.

• Members shall not disclose or authorise, to be disclosed, or use for personal gain or to benefit a third party, confidential information acquired in the course of professional practice, except with prior written permission of the employer or client, or at the direction of a court of law.

• Members shall not purport to exercise independent judgment on behalf of a client on any product or service in which they knowingly have any interest, financial or otherwise.

Ethical Behaviour?

• You have bought a CD for home use, your car has a tape deck. Is it ok to make a copy of the CD for use in the car?

• You are an IS manager, you think that one of your staff is about to leave and this will have an adverse effect on a major project. Is it ok to check over their desk when they are not there? What about their email and telephone logs?

• Under what circumstances would you recommend a hardware company with which you had a relationship with?

• Is it OK to use a company computer to play single user video games during the lunch break? Would your view be different if you were a manager?

Week Summary

• IT is a combination of hardware, software, and telecommunications systems that support business

• The essential components of an information system are hardware, software, data, processes, and people

• Companies are production oriented, service oriented, or a combination of the two

• Organization structure usually includes levels

Week Summary

• Systems analyst use modeling, prototyping, and CASE tools

• Various development methodologies exist• Regardless of the development model, it is

important to use project management tools necessary to manage people, tasks, timetables, and expenses

• An IT department develops, maintains and operates a company’s information systems

Week Summary

• Systems analysts need a combination of technical and business knowledge, analytical ability, and communication

• Week 1 complete