Modern Systems Analysis and Design PDF

Modern Systems Analysis and Design Eighth Edition, Global Edition Joseph S. Valacich Joey F. George Chapter 2 The Origins of Software Chapter 2 Copyright © 2017 Pearson Education, Ltd....

Modern Systems Analysis and Design Eighth Edition, Global Edition Joseph S. Valacich Joey F. George Chapter 2 The Origins of Software Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-1 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. Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-2 Introduction ◼ Historically, software development for a corporate information systems department was done primarily in-house. ◼ Now it involves use of components from external sources. ◼ Much in-house application coding involves making the components work together. Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-3 Introduction (cont.) ◼ Six sources of software:  Informationtechnology service firms  Packaged software providers  Vendors of enterprise-wide solution software  Cloud computing  Open-source software  In-house development ◼ There are ways to evaluate software from sources Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-4 Sources of Software ◼ Information technology services firm ◼ Packaged software producers ◼ Enterprise solutions software  Enterprise Resource Planning (ERP) ◼ Cloud computing ◼ Open source software ◼ In-house developers FIGURE 2-1 Sources of Application Software ◼ There are ways to evaluate software from sources Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-5 Systems Acquisition: Outsourcing ◼ Outsourcing: The practice of turning over responsibility of some or all of an organization’s information systems applications and operations to an outside firm Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-6 Systems Acquisition: Outsourcing (Cont.) ◼ Outsourcing Example Shell Oil outsource spending: $3.2 billion (2008) Shell’s outsourcing vendors (2008- 2011): EDS, T-Systems, AT&T, IBM, Logica, Wipro, Accenture Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-7 Outsourcing (Cont.) ◼ Reasons to outsource  Cost-effectiveness  Take advantage of economies of scale  Make up for lack of in-house knowledge  Free up internal resources  Reduce time to market  Increase process efficiencies  System development is a non-core activity for the organization  Political reasons (e.g. labor disputes) Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-8 Global Outsourcing ◼ Top outsourcing countries: India, China, Malaysia (A.T. Kearny report 2014) ◼ Top 10 are in Asia, Latin America, Europe, and Africa ◼ Some U.S. firms are switching to nearshoring (same time zone, low labor costs) Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-9 Sources of Software (Cont.) Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-10 Information Technology (IT) Services Firms ◼ Help companies develop custom information systems for internal use ◼ Develop, host, and run applications for customers ◼ Provide other services (management, accounting, auditing, financial) Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-11 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) ◼ Pre-packaged, off-the-shelf software Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-12 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% of organizations’ needs. Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-13 Prepackaged Software Figure 2-2 A document created in Microsoft’s Word (Source: Microsoft Corporation.) Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-14 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. Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-15  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. © Copyright SAP AG. All rights reserved.) Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-16 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 ◼ Pay-per-use or monthly/yearly licenses Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-17 Cloud Computing (Cont.) ◼ Examples:  Google Apps– for sharing documents, spreadsheets, and presentations  Salesforce.com – online customer relationship management (CRM) software ◼ An example of software as a service (SaaS)  MicrosoftAzure platform  Amazon.com cloud infrastructure and services ◼ An example of hardware as a service (HaaS) Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-18 Cloud Computing (Cont.) ◼ Heavy growth predicted ◼ Benefits:  Frees company of internal IT staff requirements  Faster access to application than via internal development  Lower cost than internal development ◼ Concerns  Security  Reliability  Regulation compliance Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-19 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 ◼ How to make money?  Provide maintenance/services  Sell a more featured version of the free software Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-20 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.  In-house development usually leads to more maintenance burden than other approaches ◼ Hybrid solutions involving some purchased and some in-house components are common. Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-21 Sources of Software Components Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-22 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 ◼ Functionality: the tasks that the software can perform and the mandatory, essential, and desired system features Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-23 Selecting Off-the-Shelf Software (Cont.) ◼ Vendor support: whether and how much support the vendor can provide and at what cost ◼ Viability of vendor: can vendor continue to adapt/update software to changes in systems software and hardware Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-24 Selecting Off-the-Shelf Software (Cont.) ◼ Flexibility:the ease with which software is customized ◼ Documentation: understandable and up-to-date user’s manual and technical documentation Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-25 Selecting Off-the-Shelf Software (Cont.) ◼ 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 Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-26  Validating Purchased Software Information ◼ Send a request for proposal (RFP) to vendors.  RFP – a document provided to vendors to ask them to propose hardware and system software that will meet the requirements of a new system ◼ Use a variety of information sources:  Collectinformation from vendor  Software documentation  Technical marketing literature Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-27 Request For Proposal (RFP) ◼ Sometimes called a Request For Quote (RFQ) ◼ Analyst selects best candidates based on:  vendor bids  a variety of information sources Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-28 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 ◼ Customer surveys ◼ Articles in trade publications are sometimes biased (seeded by manufacturer) Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-29 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 Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-30 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 Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-31 Reuse (Cont.) ◼ Can be effective (increased productivity, less defects, reduced rework) ◼ Technical issues – lack of methodology for component library (creating and labeling reusable components) ◼ Organizational issues – lack of commitment, training, and organizational support; hard to measure economic benefits; legal and contractual issues Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-32 Costs and Benefits of Reuse FIGURE 2-5 Investments necessary to achieve reusable components (Source: Royce, Walker, Software Project Management: A Unified Framework, 1st ed., ©1998. Reprinted and Electronically reproduced by permission of Pearson Education, Inc. Upper Saddle River, New Jersey.) Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-33 3 Steps of Software Reuse ◼ Abstraction – design of reusable piece of software ◼ Storage – making software assets available for others ◼ Recontextualization – making the software understandable to developers (Grinter, 2001) Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-34 Approaches to Reuse ◼ Ad-hoc: individuals are free to find or develop reusable assets on their own ◼ Facilitated: developers are encouraged to practice reuse ◼ Managed: the development, sharing, and adoption of reusable assets is mandated ◼ Designed: assets mandated for reuse as they are being designed for specific applications (Griss 2003) Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-35 Approaches to Reuse (Cont.) Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-36 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. Chapter 2 Copyright © 2017 Pearson Education, Ltd. 2-37