Chapter 2 The Systems Development Environment Modern Systems Analysis and Design Sixth Edition Jeffrey A. Hoffer Joey F. George Joseph S. Valacich Chapter 2 The Systems Development Environment

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall Learning Objectives Define information systems analysis and design. Describe the information Systems Development Life Cycle (SDLC). Explain Rapid Application Development (RAD), prototyping, Computer Aided Software Engineering (CASE), and Service-Oriented Architecture (SOA). Describe agile methodologies and eXtreme programming. Explain Object Oriented Analysis and Design and the Rational Unified Process (RUP). Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall Introduction Information Systems Analysis and Design The process of developing and maintaining an information system. Complex organizational process Used to develop and maintain computer-based information systems Used by a team of business and systems professionals Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall Introduction (Cont.) FIGURE 1-1 An organizational approach to systems analysis and design is driven by methodologies, techniques, and tools Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall Introduction (Cont.) Methodologies are a sequence of step-by-step approaches that help develop your final product: the information system. 6/10/2018Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall Introduction (Cont.) Techniques are processes that ensure that your work is well thought-out, complete, and comprehensible to others on your project team. Techniques provide support for a wide range of tasks, including conducting thorough interviews with current and future users of the information system to determine what your system should do, planning and managing the activities in a systems development project, diagramming how the system will function, and designing the reports, such as invoices, your system will generate for its users to perform their jobs. 6/10/2018Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall Introduction (Cont.) Tools are computer programs, such as computer-aided software engineering (CASE) tools, that make it easy to use specific techniques. 6/10/2018Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall Introduction (Cont.) These three elements methodologies, techniques tools work together to form an organizational approach to systems analysis and design. 6/10/2018Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

A Modern Approach to Systems Analysis and Design (Cont.) Application Software Software designed to process data and support users in an organization. Examples include spreadsheets, word processors, and database management systems. Systems Analyst Organizational role most responsible for analysis and design of information systems Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall System and its parts System A system is an interrelated set of business procedures (or components) used within one business unit, working together for some purpose. For example, a system in the payroll department keeps track of checks, whereas an inventory system keeps track of supplies. Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall System and its parts Seven characteristics of a system (explained later) Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall System and its parts System Parts or Components A component is either an irreducible part or an aggregate of parts, also called a subsystem. For example, just as with an automobile or a stereo system, with proper design, we can repair or upgrade the system by changing individual components without having to make changes throughout the entire system. Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall System and its parts System Parts or Components The components are interrelated; that is, the function of one is somehow tied to the functions of the others. For example, the work of one component, such as producing a daily report of customer orders received, may not progress successfully until the work of another component is finished, such as sorting customer orders by date of receipt. Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall System and its parts System Parts or Components A system has a boundary, within which all of its components are contained and which establishes the limits of a system, separating it from other systems. Components within the boundary can be changed, whereas systems outside the boundary cannot be changed. Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall System and its parts System Parts or Components All of the components work together to achieve some overall purpose for the larger system: the system’s reason for existing (i.e. the overall goal or function of a system) Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall System and its parts System Parts or Components Environment: Everything external to a system that interacts with the system. Interface: Point of contact where a system meets its environment or where subsystems meet each other. Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall System and its parts System Parts or Components For example, the environment of a state university includes prospective students, foundations and funding agencies, and the news media. Usually the system interacts with its environment. A university interacts with prospective students by having open houses and recruiting from local high schools. An information system interacts with its environment by receiving data (raw facts) and information (data processed in a useful format). Figure (next slide) shows how a university can be seen as a system. Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall A university as a system 6/10/2018Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall System and its parts System Parts or Components In its functioning, a system must face constraints — the limits (in terms of capacity, speed, or capabilities) to what it can do and how it can achieve its purpose within its environment. Some of these constraints are imposed inside the system (e.g., a limited number of staff available), and others are imposed by the environment (e.g., due dates or regulations). A system takes input from its environment in order to function. People, for example, take in food, oxygen, and water from the environment as input. Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Developing Information Systems System Development Methodology is a standard process followed in an organization to conduct all the steps necessary to analyze, design, implement, and maintain information systems. Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Systems Development Life Cycle (SDLC) Traditional methodology used to develop, maintain, and replace information systems. Phases in SDLC: Planning Analysis Design Implementation Maintenance Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Standard and Evolutionary Views of SDLC FIGURE 1-3 Evolutionary model FIGURE 1-2 The systems development life cycle Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Systems Development Life Cycle (SDLC) (Cont.) Planning – an organization’s total information system needs are identified, analyzed, prioritized, and arranged Analysis – system requirements are studied and structured Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Systems Development Life Cycle (SDLC) (Cont.) Design – a description of the recommended solution is converted into logical and then physical system specifications Logical design – all functional features of the system chosen for development in analysis are described independently of any computer platform Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Systems Development Life Cycle (SDLC) (Cont.) Physical design – the logical specifications of the system from logical design are transformed into the technology-specific details from which all programming and system construction can be accomplished Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Systems Development Life Cycle (SDLC) (Cont.) Implementation – the information system is coded, tested, installed and supported in the organization Maintenance – an information system is systematically repaired and improved Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

The Heart of the Systems Development Process FIGURE 1-7 The analysis–design–code–test loop Current practice combines analysis, design, and implementation into a single iterative and parallel process of activities. Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Traditional Waterfall SDLC One phase begins when another completes, with little backtracking and looping. FIGURE 1-9 A traditional waterfall SDLC Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

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 Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Different Approaches to Improving Development CASE Tools Rapid Application Development (RAD) Agile Methodologies eXtreme Programming Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Computer-Aided Software Engineering (CASE) Tools Diagramming tools* enable graphical representation. Computer displays and report generators help prototype how systems “look and feel”. Examples: Rational Rose, SmartDraw, Microsoft Visio, etc. * https://en.wikipedia.org/wiki/List_of_Unified_Modeling_Language_tools Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Computer-Aided Software Engineering (CASE) Tools (Cont.) Analysis tools automatically check for consistency in diagrams, forms, and reports. A central repository provides integrated storage of diagrams, reports, and project management specifications. Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Computer-Aided Software Engineering (CASE) Tools (Cont.) Documentation generators standardize technical and user documentation. Code generators enable automatic generation of programs and database code directly from design documents, diagrams, forms, and reports. Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall CASE Tools (Cont.) FIGURE 1-10 A class diagram from IBM’s Rational Rose (Source: IBM) Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall CASE Tools (Cont.) Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Rapid Application Development (RAD) Methodology to radically decrease design and implementation time Involves: extensive user involvement, prototyping, JAD sessions, integrated CASE tools, and code generators Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Rapid Application Development (RAD) (Cont.) FIGURE 1-11 RAD life cycle Cutover: Testing, installation, user training … Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Service-Oriented Architecture (SOA) An approach to systems development based on building complete systems through assembling software components, each of which model generic business functions Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Service-Oriented Architecture (SOA) A service-oriented architecture (SOA) is an architectural pattern in computer software design in which application components provide services to other components via a communications protocol, typically over a network. The principles of service-orientation are independent of any vendor, product or technology. [Wikipedia] Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Service-Oriented Architecture (SOA) (Cont.) FIGURE 1-12 Illustration of a service, a credit check, used by applications and other services Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 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 Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall Agile Methodologies Agile software development is a group of software development methods in which solutions evolve through collaboration between self-organizing,[1] cross-functional teams. It promotes adaptive planning, evolutionary development, early delivery, continuous improvement, and encourages rapid and flexible response to change.[2] [Wikipedia] 6/10/2018Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall The Agile Methodologies group argues that software development methodologies adapted from engineering generally do not fit with real-world software development. Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

When to use Agile Methodologies If your project involves: Unpredictable or dynamic requirements Responsible and motivated developers Customers who understand the process and will get involved Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall eXtreme Programming Short, incremental development cycles Automated tests Two-person programming teams Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

eXtreme Programming (Cont.) Coding and testing operate together Advantages: Communication between developers High level of productivity High-quality code Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Object-Oriented Analysis and Design (OOAD) Based on objects rather than data or processes Object: a structure encapsulating attributes and behaviors of a real-world entity Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Object-Oriented Analysis and Design (OOAD) (Cont.) 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 Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Rational Unified Process (RUP) An object-oriented systems development methodology RUP establishes four phase of development: inception, elaboration, construction, and transition. Each phase is organized into a number of separate iterations. Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall FIGURE 1-13 Phases of OOSAD-based development Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall Summary In this chapter you learned how to: Define information systems analysis and design. Describe the information Systems Development Life Cycle (SDLC). Explain Rapid Application Development (RAD), prototyping, Computer Aided Software Engineering (CASE), and Service-Oriented Architecture (SOA). Describe agile methodologies and eXtreme programming. Explain Object Oriented Analysis and Design and the Rational Unified Process (RUP). Chapter 1 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Printed in the United States of America. Copyright © 2011 Pearson Education, Inc.   Publishing as Prentice Hall