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Chapter 1 The Systems Development Environment Modern Systems Analysis and Design Sixth Edition Jeffrey A. Hoffer Joey F. George Joseph S. Valacich
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 2 Chapter 1 Learning Objectives Define information systems analysis and design. Describe the information Systems Development Life Cycle (SDLC). Explain Rapid Application Development (RAD), Computer Aided Software Engineering (CASE), Service-Oriented Architecture (SOA). Describe agile methodologies eXtreme programming. Explain Object Oriented Analysis and Design the Rational Unified Process (RUP).
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 3 Chapter 1 Introduction Information Systems Analysis and Design Complex organizational process Used to develop and maintain computer-based information systems Used by a team of business and systems professionals Information technology: capabilities => based on organizational perspective (Application Software) Organization: a whole enterprise, specific departments, individual working groups
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall Introduction (Cont.) 4 Chapter 1 FIGURE 1-1 An organizational approach to systems analysis and design is driven by methodologies, techniques, and tools
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Introduction Methodologies A sequence of step-by-step approaches that help develop the information system Organization’s orientation=> consensus management Techniques Processes that the analyst follows to ensure thorough, complete and comprehensive analysis and design Interviews, Planning and managing activities, Diagramming Tools Computer programs that aid in applying techniques Techniques and tools: based on Organization’s system development methodology Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 5 8/28/2015Chapter 1
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 6 Chapter 1 A Modern Approach to Systems Analysis and Design 1950s: focus on efficient automation of existing processes: by purchasing Computer power: efficiency of processing Machine language 1960s: advent of 3GL, faster and more reliable computers Computer programming language Smaller, faster, less-expensive computers Most organization develop their own applications (in-house development) 1970s: system development becomes more like an engineering discipline Database management systems
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 7 Chapter 1 A Modern Approach to Systems Analysis and Design (Cont.) 1980s: major breakthrough with 4GL, CASE tools, object oriented methods Microcomputers: Many off-the-shelf software Window and icon-based interface Less software in-house but more software from software vendors => les developers, more integrators 1990s: focus on system integration, GUI applications, client/server platforms, Internet: complex systems Visual programming environment: VisualBasic Buy entire enterprise system from software developing companies: SAP The new century: Web application development, wireless PDAs, component-based applications
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 8 Chapter 1 A Modern Approach to Systems Analysis and Design (Cont.) Application Software Computer software designed to support organizational functions or processes Systems Analyst Organizational role most responsible for analysis and design of information systems Data and applications Data, information Data flow, processing logic System Analyst need people method IT
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 9 Chapter 1 Developing Information Systems System Development Methodology is a standard process followed in an organization to conduct all the steps necessary to analyze, design, implement, maintain information systems.
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 10 Chapter 1 Systems Development Life Cycle (SDLC) Traditional methodology used to develop, maintain, and replace information systems. Phases in SDLC: Planning Analysis Design Implementation Maintenance
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 11 Chapter 1 Standard and Evolutionary Views of SDLC FIGURE 1-3 Evolutionary model FIGURE 1-2 The systems development life cycle
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 12 Chapter 1 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
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 13 Chapter 1 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
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 14 Chapter 1 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
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 15 Chapter 1 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
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 16 Chapter 1
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall FIGURE 1-8 The heart of systems development Chapter 1 The Heart of the Systems Development Process Current practice combines analysis, design, and implementation into a single iterative and parallel process of activities. FIGURE 1-7 The analysis–design–code–test loop
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 18 Chapter 1 Traditional Waterfall SDLC One phase begins when another completes, with little backtracking and looping. FIGURE 1-9 A traditional waterfall SDLC
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 19 Chapter 1 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 of sound development practices
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 20 Chapter 1 Different Approaches to Improving Development CASE Tools Rapid Application Development (RAD) Agile Methodologies eXtreme Programming
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 21 Chapter 1 Computer-Aided Software Engineering (CASE) Tools Diagramming tools enable graphical representation. Computer displays report generators help prototype how systems “look and feel”.
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 22 Chapter 1 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.
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 23 Chapter 1 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.
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 24 Chapter 1 CASE Tools (Cont.) FIGURE 1-10 A class diagram from IBM’s Rational Rose (Source: IBM)
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall CASE Tools (Cont.) 25 Chapter 1
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 26 Chapter 1 Rapid Application Development (RAD) Methodology to radically decrease design and implementation time Involves: extensive user involvement, prototyping, Joint Application Design(JAD) sessions: users, managers analysts => review system requirements, integrated CASE tools, code generators
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 27 Chapter 1 Rapid Application Development (RAD) (Cont.) FIGURE 1-11 RAD life cycle
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 28 Chapter 1 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
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 29 Chapter 1 Service-Oriented Architecture (SOA) (Cont.) FIGURE 1-12 Illustration of a service, a credit check, used by applications and other services
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 30 Chapter 1 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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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 31 Chapter 1 The Agile Methodologies group argues that software development methodologies adapted from engineering generally do not fit with real- world software development.
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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 32 Chapter 1
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 33 Chapter 1
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 34 Chapter 1 eXtreme Programming Short, incremental development cycles Automated tests Two-person programming teams
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 35 Chapter 1 eXtreme Programming (Cont.) Coding and testing operate together Advantages: Communication between developers High level of productivity High-quality code
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 36 Chapter 1 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
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 37 Chapter 1 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
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 38 Chapter 1 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).
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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. Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall
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Summary
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Chapter 2 The Origins of Software Modern Systems Analysis and Design Sixth Edition Jeffrey A. Hoffer Joey F. George Joseph S. Valacich
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 42 Chapter 2 Learning Objectives Explain outsourcing. Describe six different sources of software. Discuss how to evaluate off-the-shelf software. Explain reuse and its role in software development.
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 43 Chapter 2 Introduction There are various sources of software for organizations. There are criteria to evaluate software from different sources.
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 44 Chapter 2 Systems Acquisition: Outsourcing Outsourcing: Turning over responsibility of some or all of an organization's information systems applications and operations to an outside firm
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 45 Chapter 2 Systems Acquisition: Outsourcing (Cont.) Outsourcing Examples A company that runs payroll applications for clients A company that runs your applications at your site
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 46 Chapter 2 Outsourcing (Cont.) Reasons to outsource Cost-effective Take advantage of economies of scale Free up internal resources Reduce time to market Increase process efficiencies System development is a non-core activity for the organization
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 47 Chapter 2 Sources of Software Information technology services firm Packaged software producers Enterprise-wide solutions Application service providers (ASPs) Open source software In-house developers
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 48 Chapter 2 Sources of Software (Cont.) FIGURE 2-1 Sources of Application Software
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 49 Chapter 2 Information Technology (IT) Services Firms Help companies develop custom information systems for internal use. Develop, host, and run applications for customers. Provide other services.
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 50 Chapter 2 Packaged Software Producers Serve many market segments. Provide software ranging from broad- based packages (i.e. general ledger) to niche packages (i.e. day care management).
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 51 Chapter 2 Packaged Software Producers (Cont.) Software runs on all size computers, from microcomputers to large mainframes. Prepackaged software is off-the-shelf, turnkey software (i.e. not customizable). Off-the-shelf software at best meets 70 percent of organizations’ needs.
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall Packaged Software Producers (Cont.) 52 Chapter 2
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 53 Chapter 2 Prepackaged Software Figure 2-2 Microsoft Project
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 54 Chapter 2 Enterprise Solutions Software Enterprise Resource Planning (ERP) systems integrate individual traditional business functions into modules enabling a single seamless transaction to cut across functional boundaries. SAP AG is the leading vendor of ERP systems.
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 55 Chapter 2 Enterprise Solutions Software (Cont.) Figure 2-3 SAP’s Business ByDesign, a product designed for medium sized companies. (Source: www.sap.com/usa/solutions/Sme/Businessbydesign/Flash/bsm/A1S.html )
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 56 Chapter 2 Cloud Computing The provision of computing resources, including applications, over the Internet, so customers do not have to invest in the computing infrastructure needed to run and maintain the resources
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Introduction to Cloud Computing refer to: http://thumbsup.in.th/2012/10/vocabulary-cloud-computing/
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Introduction to Cloud Computing refer to: http://thumbsup.in.th/2012/10/vocabulary-cloud-computing/
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 59 Chapter 2 Open Source Software Freely available including source code Developed by a community of interested people Performs the same functions as commercial software Examples: Linux, mySQL, Firefox
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 60 Chapter 2 In-House Development If sufficient system development expertise with the chosen platform exists in-house, then some or all of the system can be developed by the organization’s own staff. Hybrid solutions involving some purchased and some in-house components are common.
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall Sources of Software Components 61 Chapter 2
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 62 Chapter 2 Selecting Off-the-Shelf Software Cost: comparing the cost of developing the same system in-house with the cost of purchasing or licensing the software package
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 63 Chapter 2 Functionality: the tasks that the software can perform and the mandatory, essential, and desired system features Selecting Off-the-Shelf Software
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 64 Chapter 2 Selecting Off-the-Shelf Software Vendor support: whether or how much support the vendor can provide and at what cost
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 65 Chapter 2 Viability of vendor: can the software adapt to changes in systems software and hardware Selecting Off-the-Shelf Software
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 66 Chapter 2 Selecting Off-the-Shelf Software Flexibility: how easy it is to customize the software Documentation: is the user’s manual and technical documentation understandable and up- to-date
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 67 Chapter 2 Selecting Off-the-Shelf Software Response time: how long it takes the software package to respond to the user’s requests in an interactive session Ease of installation: a measure of the difficulty of loading the software and making it operational
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 68 Chapter 2 Validating Purchased Software Information Use a variety of information sources: Collect information from vendor Software documentation Technical marketing literature
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 69 Chapter 2 Request For Proposal (RFP) Request for proposal (RFP) is a document provided to vendors to ask them to propose hardware and system software that will meet the requirements of a new system.
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 70 Chapter 2 Request For Proposal (RFP) (Cont.) Sometimes called a Request For Quote (RFQ) Use a variety of information sources Based on vendor bids, analyst selects best candidates.
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 71 Chapter 2 Information Sources For RFP Vendor’s proposal Running software through a series of tests Feedback from other users of the vendor’s product Independent software testing services Articles in trade publications
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 72 Chapter 2 Reuse The use of previously written software resources, especially objects and components, in new applications Commonly applied to two different development technologies: Object-oriented development Component-based development
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 73 Chapter 2 Reuse (Cont.) Object-oriented development Object class encapsulates data and behavior of common organizational entities (e.g. employees) Component-based development Components can be as small as objects or as large as pieces of software that handle single business functions.
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 74 Chapter 2 Reuse (Cont.) Object-oriented development reuse is the use of object classes in more than one application (e.g. Employee).
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 75 Chapter 2 Reuse (Cont.) Component-based development reuse is the assembly of an application from many different components at many different levels of complexity and size (e.g. Currency conversion).
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 76 Chapter 2 Costs and Benefits of Reuse FIGURE 2-5 Investments necessary to achieve reusable components (Source: Royce, 1998, used by permission.)
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 77 Chapter 2 Approaches to Reuse Ad-hoc: individuals are free to find or develop reusable assets on their own. Facilitated: developers are encouraged to practice reuse.
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 78 Chapter 2 Approaches to Reuse (Cont.) Managed: the development, sharing, and adoption of reusable assets is mandated. Designed: assets mandated for reuse as they are being designed for specific applications.
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall Approaches to Reuse (Cont.) 79 Chapter 2
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Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall 80 Chapter 2 Summary In this chapter you learned how to: Explain outsourcing. Describe six different sources of software. Discuss how to evaluate off-the-shelf software. Explain reuse and its role in software development.
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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. Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall
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