Nt1310 Unit 1 Assignment 1

Introduction to SAD

LIS 163 Sir Igor

Introduction
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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

The Impact of Information Technology
Information Technology
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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 Impact of Information Technology
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The Role of SAD
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Systems Analysis and Design Systems Analyst
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Step-by-step
process for developing high-quality information systems Plan, develop, and maintain information systems Combines information technology, people and data to support business requirements

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Information System

The Impact of Information Technology
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Who develops Information Systems?
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In-house applications Software packages Internet-based application services Outsourcing Custom solutions Enterprise-wide software strategies How versus What

The Impact of Information Technology
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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
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The Impact of Information Technology
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Information System Components
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Hardware
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Moore’s Law

Is the physical layer of the information system

The Impact of Information Technology
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Information System Components
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System software Network operating system Application software Enterprise applications Horizontal system
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Software

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Vertical system
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A basic system, such as an inventory or payroll package that is commonly used by a variety of companies.
A system designed to meet the unique requirements of a specific business or industry, such as a Web-based retailer or video rental chain.

The Impact of Information Technology
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Information System Components
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Data
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Processes
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Is the raw material that an information system transforms into useful information Define the tasks and business functions that users, managers, and IT staff members perform to achieve specific results Users, or end users, are the people who interact with an information system, both inside and outside the
company

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People
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Understanding the Business
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Systems analysts use a process called business process modeling to represent a company's operations and information needs. Business Profile
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A business profile defines a company's overall functions, processes, organization, products, services, customers, suppliers, competitors, constraints, and future direction.

Understanding the Business

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Business Model
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A business model graphically represents business functions that consist of business processes, such as sales, accounting, and purchasing.

Understanding the Business
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Business Process
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A business process describes specific events, tasks, and desired results. An attempt by companies to simplify operations or reduce costs.

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Business Process Reengineering
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Understanding the Business

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Product-oriented vs Service-oriented Internet-dependent vs Brick and Mortar

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Impact of the Internet
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E-commerce / I-commerce
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Business-to-Business (B2B)
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A commercial exchange (e.g. products or services) between businesses, typically enabled by the internet or electronic means. A commercial exchange (e.g. products or services) between businesses and consumers conducted over the internet.

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Business-to-Consumer (B2C)
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Web-based Systems Development

How Business Uses Information Systems
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In the 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

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

Knowledge management systems
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Business support systems
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Efficient because they process a set of transaction-related commands as a group rather than individually Provide job-related information to users at all levels of a company Management information systems (MIS) Radio frequency identification (RFID) What-if

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User productivity systems
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Called expert systems Simulate human reasoning by combining a knowledge base and inference rules Many use fuzzy logic Technology that improves productivity Word processing is an example

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Information systems integration
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Most large companies require systems that combine transaction processing, business support, knowledge management, and user productivity features

Information System Users and Their Needs
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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.

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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Systems Development Tools and Techniques
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Modeling
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Prototyping
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Used to describe and simplify an information system: Business model Requirements model Data model Object model Network model Process model

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Early working version of an information system 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 – Framework for systems development and support a wide variety of design methodologies – CASE tools

Systems Development Methods
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Structured Analysis O-O Analysis JAD RAD

Systems Development Life Cycle

Problems with Waterfall Approach
System requirements “locked in” after being determined (can't change) ● Limited user involvement (only in requirements phase) ● Too much focus on milestone deadlines of SDLC phases to the detriment (harm) of sound development practices
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Alternatives to Waterfall SDLC

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Prototyping ● CASE tools ● Joint Application Design (JAD) Rapid Application Development (RAD) ● Agile Methodologies ● eXtremeProgramming
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Prototyping

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Requirements quickly converted to a working system System is continually revised Close collaboration between users and analysts

Adapted from: Prototyping: the new paradigm for systems development.
J.D. Naumann and A.M. Jenkins. 1982.

CASE Tools

Computer-Aided Software Engineering ● Software tools providing automated support for systems development ● Project dictionary/workbook: system description and specifications ● Diagramming tools
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Joint Application Design (JAD)
Structured process involving users, analysts, and managers ● Several-day intensive workgroup sessions (intensive structured meetings) ● All people affected by IS in one room all at the same time ● Purpose: to specify or review system requirements ● “Shared understanding”
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Rapid Application Development (RAD)
Methodology to decrease design and implementation time ● Involves: prototyping, JAD, CASE tools, and code generators
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Agile Methodologies
Motivated by recognition of software development as fluid, unpredictable, and dynamic ● Three key principles ● Adaptive rather than predictive ● Emphasize people rather than roles ● Self-adaptive
processes
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eXtreme Programming

Short, incremental development cycles ● Automated tests ● Two-person programming teams ● Coding and testing operate together ● Advantages:
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Communication between developers ● High level of productivity ● High-quality code
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Object-Oriented Analysis and Design
Based on objects rather than data or processes ● Object: a structure encapsulating attributes and behaviors of a real-world entity ● Object class: a logical grouping of objects sharing the same attributes and behaviors ● Inheritance: hierarchical arrangement of classes enable subclasses to inherit properties of superclasses
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Rational Unified Process (RUP) involves an iterative, incremental approach to systems development

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Hoffer, Jeffrey A. et al.
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Systems Analysis and Design Methods. Systems Analysis and Design.

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Shelly, Gary B. et al.
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