0da740ace917ac023b8eff8823f00c91.ppt
- Количество слайдов: 49
Accounting Information Systems 9 th Edition Marshall B. Romney Paul John Steinbart © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 17 -1
AIS Development Strategies Chapter 17 © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 17 -2
Learning Objectives 1. 2. 3. Describe how organizations purchase application software, vendor services, and hardware. Explain how information system departments develop custom software. Explain how end users develop, use, and control computer-based information systems. © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 3
Learning Objectives 4. 5. Explain why organizations outsource their information systems, and evaluate the benefits and risks of this strategy. Explain the principles and challenges of business process reengineering. © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 4
Learning Objectives 6. 7. Describe how prototypes are used to develop an AIS, and discuss the advantages and disadvantages of doing so. Explain what computer-aided software engineering is and how it is used in systems development. © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 5
Introduction ¢ ¢ Ann Christy was elated that the new system Shoppers Mart (SM) needed was approved. She needed answers to the following questions: l Was the software she needed available for her to purchase? If so, how should she approach the process of buying hardware and software and selecting a vendor? © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 6
Introduction l l l How do companies go about developing software in house, and is the best approach for SM? How extensively should the system make use of end-user-developed software? If the company decided to develop the system in house, should it try and speed up the development process by using prototyping or computer-assisted software engineering? © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 7
Introduction l l Should SM just make the needed improvements to its existing system, or should it consider reengineering its business processes and then develop a system to support the new processes? Was outsourcing the information system a viable alternative to obtaining a new system? Did the benefits outweigh its risks? © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 8
Introduction This chapter discusses three ways to obtain a new information system: purchasing prewritten software, developing software in house, and hiring an outside company (outsourcing). ¢ It also presents ways of speeding up or improving the development process. ¢ © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 9
Learning Objective 1 Describe how organizations purchase application software, vendor services, and hardware. © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 10
Purchase Software Canned software is written by computer manufacturers or software development companies. ¢ It is sold on the open market to a broad range of users with similar requirements. ¢ Turnkey systems are a combination of software and hardware sold as a package. ¢ © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 11
Purchasing Software and The SDLC ¢ Companies that buy rather than develop AIS software still go through the systems development life cycle (SDLC). 1. 2. 3. 4. 5. Systems analysis Conceptual design Physical design Implementation and conversion Operation and maintenance © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 12
The Systems Acquisition Process Investigate software packages Will package meet needs? Yes Send RFP for software and hardware Evaluate proposal No Can package be modified? No Develop software internally Yes Send RFP for hardware, if necessary Select best © 2003 Prentice Hall Business Publishing, combination Accounting Information Systems, 9/e, Romney/Steinbart 13
Learning Objective 2 Explain how information system departments develop custom software. © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 14
Development by In-House IS Department In the past, most organizations had their information system departments develop custom software, because canned software that fit their specific needs was not available. ¢ Developing custom software is difficult and error-prone. ¢ It also consumes a great deal of time and resources. ¢ © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 15
Development by In-House IS Department ¢ ¢ ¢ Custom software is usually developed and written in house. Alternatively, organizations may engage an outside company to develop a package or assemble it from their inventory of program modules. When contracting with an outside organization, a company should maintain control over the development process. © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 16
Development by In-House IS Department ¢ What guidelines are recommended? – – – carefully select a developer sign a contract plan and monitor each step maintain effective communication control all costs © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 17
Learning Objective 3 Explain how end users develop, use, and control computer-based information systems. © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 18
End-User-Developed Software ¢ ¢ End-user computing (EUC) is the hands-on development, use, and control of computerbased information systems by users. When end users began to meet their initial information needs two things happened: 1 2 Users realized computers could be used to meet more and more information needs. Increased access to data created many new uses and needs for information. © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 19
End-User-Developed Software ¢ What are some examples of end-user development uses? – – – retrieving information from company databases to produce simple reports or to answer one-time queries performing “what if” sensitivity or statistical analyses developing applications using prewritten software (spreadsheet or database system) © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 20
End-User-Developed Software Benefits of End-User Computing User creation, control, and implementation Systems that meet user needs Timeliness Freeing up IS resources Versatility and ease of use © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 21
End-User-Developed Software Risks of End-User Computing Logic and development errors Inadequately tested applications Inefficient systems Poorly controlled and documented systems Systems incompatibility Duplication of systems Increased costs © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 22
End-User-Developed Software ¢ Which one is an approach organizations use to manage and control end-user computing? – ¢ help desk What are some duties of the help desk? – – providing hot-line assistance to help resolve problems serving as a clearinghouse for information, coordination, and assistance © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 23
End-User-Developed Software – – – training end users, and providing corresponding technical maintenance and support evaluating new end-user hardware and software products assisting with application development developing and implementing standards controlling data © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 24
Learning Objective 4 Explain why organizations outsource their information systems, and evaluate the benefits and risks of this strategy. © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 25
Outsource the System ¢ What is outsourcing? l ¢ It is hiring an outside company to handle all or part of an organization’s data processing activities. In a mainframe outsourcing agreement, the outsourcers buy their client’s computers and hire all or most of the client’s employees. © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 26
Outsource the System ¢ In a client/server or PC outsourcing agreement, an organization outsources a particular service, a segment of its business, a particular function, or PC support. © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 27
Outsource the System Benefits of Outsourcing A business solution Asset utilization Access to greater expertise and more advanced technology Lower costs Improved development time Elimination of peaks and valleys usage Facilitation of downsizing © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 28
Outsource the System Risks of Outsourcing Inflexibility Loss of control Reduced competitive advantage Locked -in system Unfulfilled goals © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 29
Learning Objective 5 Explain the principles and challenges of business process reengineering. © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 30
Business Processes Reengineering ¢ ¢ ¢ What is business process reengineering (BPR)? It is the thorough analysis and complete redesign of business process and information systems to achieve performance improvements. It is a process that challenges traditional organizational values and cultures associated with underperformance. © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 31
Business Processes Reengineering BPR reduces a company to its essential business processes and focuses on why they are done rather than on the details of how they are done. ¢ It completely reshapes organizational work practices and information flows to take advantage of technological advancements. ¢ © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 32
Principles of Reengineering ¢ What are the seven principles of business processing reengineering? 1. 2. 3. Organize around outcomes, not tasks. Have output users perform the process. Have those who produce information process it. © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 33
Principles of Reengineering 4. 5. 6. 7. Centralize and disperse data. Integrate parallel activities. Empower workers, use built-in controls, and flatten the organization chart. Capture data once, at its source. © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 34
Challenges Faced by Reengineering Efforts ¢ What are some of the obstacles to reengineering efforts? – – – tradition resistance time requirements lack of management support risk © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 35
Challenges Faced by Reengineering Efforts – – – skepticism retraining controls © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 36
Learning Objective 6 Describe how prototypes are used to develop an AIS, and discuss the advantages and disadvantages of doing so. © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 37
Prototyping ¢ What is prototyping? – ¢ an approach to systems design in which a simplified working model of a system is developed. A prototype, or “first draft, ” is quickly and inexpensively built and provided to users for testing. © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 38
Prototyping ¢ What four steps are involved in developing a prototype? 1. 2. 3. 4. Identify basic systems requirements. Develop an initial prototype that meets the agreed-on requirements. Users identify changes, developers make changes, and the system is turned over to the user. Use the system approved by the users. © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 39
Prototyping Advantages of Prototyping Better definition of user needs Higher user involvement and satisfaction Faster development time Fewer errors More opportunity for changes Less costly © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 40
End-User-Developed Software Disadvantages of Prototyping Significant user time Less efficient use of system resources Incomplete systems development Inadequately tested and documented systems Negative behavioral reactions Unending development © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 41
Learning Objective 7 Explain what computer-aided software engineering is and how it is used in systems development. © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 42
Computer-Aided Software Engineering (CASE) ¢ ¢ ¢ CASE is an integrated package of computer-based tools that automate important aspects of the software development process. CASE tools are used to plan, analyze, design, program, and maintain an information system. They are also used to enhance the efforts of managers, users, and programmers in understanding information needs. © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 43
Computer-Aided Software Engineering (CASE) ¢ ¢ CASE tools do not replace skilled designers; instead they provide a host of self-integrated tools that give developers effective support for all SDLC phases. CASE software typically has tools for strategic planning, project and system management, database design, screen and report layout, and automatic code generation. © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 44
Computer-Aided Software Engineering (CASE) Advantages of CASE Technology Improved productivity Improved program quality Cost savings Improved control procedures Simplified documentation © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 45
Computer-Aided Software Engineering (CASE) Disadvantages of CASE Technology Incompatibility Unmet expectations © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 46
Case Conclusion ¢ What did Ann Christy decide? – ¢ What did she think about prototyping? – ¢ against outsourcing the AIS that it would not work well What did she think about reengineering? – that the system did not need reengineering © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 47
Case Conclusion ¢ What were her options? – ¢ purchase a system or design one in house. No matter which approach she chose, Ann wanted to facilitate as much end-user development as was practical and useful. © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 48
End of Chapter 17 © 2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart 49
0da740ace917ac023b8eff8823f00c91.ppt