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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 1 Systems Development: A Survey Chapter 11
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 2 Overview l Systems development is the process of modifying or replacing a portion or all of an information system. l This process requires a substantial commitment of time and resources and is an ongoing activity in many organizations.
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 3 Organizational Context of Systems Development l In information systems terminology, a user or end user is an organizational function other than the information system function that requires computer data processing. l The information system function is separate from user functions.
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 4 Organizational Context of Systems Development Systems Analysis Systems Analysis Systems Design Systems Design Operations Users Information Systems System Output System Requirements
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 5 Systems Analysis l Systems analysis is responsible for the development of the general design of system applications. l Systems analysis works with users to define their specific information requirements. l These requirements are then communicated to the systems design function.
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 6 Systems Analysis l There are four general phases in systems analysis: 1 Survey the existing system. 2 Identify the information needs of users. 3 Identify the system requirements that are necessary to satisfy the information needs of users. 4 Prepare a systems analysis report.
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 7 Systems Design l What is systems design? l There are three general phases in systems design. l What are these three phases? 1 Evaluate alternative designs for the proposed system. 2 Prepare detailed design specifications. 3 Prepare the systems design report.
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 8 Operations l The operations subfunction of information systems actually operates the computer equipment. l Implementation occurs when newly developed systems are actually up and running on the computer equipment.
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 9 Systems Development Life Cycle l Systems development projects normally are undertaken by a project team. l This team is composed of system analysts, programmers, accountants, and other people who are knowledgeable about or affected by the project. l Every systems development project goes through essentially the same life cycle.
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 10 Systems Development Life Cycle Analysis Design Implementation
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 11 Systems Development Life Cycle l The life-cycle concept implies that each systems development project should be factored into a number of distinct phases with formal management control points. l The basic control principle is that each phase should generate documentation to be formally reviewed and approved prior to entering the next phase of a project’s life cycle.
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 12 Systems Development Life Cycle General PhasesDetailed Phases AnalysisFeasibility assessment Information analysis AnalysisFeasibility assessment Information analysis Design System design Program development Design System design Program development ImplementationConversion Operation and maintenance Audit and review ImplementationConversion Operation and maintenance Audit and review
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 13 Problems with Systems Development Life Cycle Wild EnthusiasmDisillusionment Total Confusion
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 14 Problems with Systems Development Life Cycle Search for the Guilty Punishment of the Innocent Promotion of Nonparticipants
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 15 Problems with Systems Development Life Cycle As Proposed by User Manager As Approved by the Steering Committee As Structured by the Data Administrator
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 16 Problems with Systems Development Life Cycle As Designed by the Lead Analyst As Implemented by the Application Programmers What the User Actually Wanted
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 17 Business Reengineering l What is business reengineering? l What has stimulated interest in business reengineering? – total quality performance (TQP), or TQM – trends in information services
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 18 Business Reengineering l Business reengineering concerns business reinvention (not improvement), enhancement, or modification. l Business reengineering is concerned with multiplicative rather than marginal improvements in performance.
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 19 The Role of Information Technology l Information technology is a powerful enabler of process innovation. l There are nine categories of ways in which information technology can support process innovation: 1 Automational support 2 Informational support
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 20 The Role of Information Technology 3 Sequential support 4 Tracking support 5 Analytical support 6 Geographical support 7 Integrative support 8 Intellectual support 9 Disintermediating support
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 21 Documentation Standards l Documentation standards set forth explicit requirements for the documentation to be developed during a project. l The basic concept of system development standards is to define the phases in the systems development life cycle and to specify the documents that should be generated during each phase.
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 22 Overview of Systems Development Documentation l feasibility study ? l Logical flow diagrams ? l data dictionary ? l user specification ? l conceptual design report ? l systems design report ? l program description ?
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 23 Overview of Systems Development Documentation l run manual ? l Data entry procedures ? l What is a conversion plan? l testing plan ?
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 24 Overview of Systems Development Documentation Module A Module B Module C Old System New System Old System New System Immediate Cutover Phased Conversion Parallel Operation Time
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 25 Maintenance of Systems Documentation Standards l Maintaining systems documentation standards and using them consistently in systems development are formidable tasks. l Documentation standards my be developed in-house or purchased from a vendor. l Documentation is frequently referred to as deliverables.
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 26 Analyst/Programmer Productivity Control l The major portion of total systems development costs is the salaries of analysts and programmers. l The end product of an analyst is a system design for a program, which is not as concrete as an actual program.
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 27 Analyst/Programmer Productivity Control l The use of structured analysis, design, and graphic techniques should increase the overall productivity of the analyst function. l Controls suggested for improving the productivity of programmers concern the way programs are designed and coded and the organization of programming personnel.
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 28 Structured Programming l What is structuring programming? l The team approach establishes a team consisting of a lead or chief programmer, assistant programmers as needed, and a programming secretary.
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 29 Structured Programming l Programmer productivity may also be increased through technical aids. l Special software packages, called preprocessors, and automated documentation systems also increase programmer productivity.
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 30 Computer-Aided Software Engineering (CASE) Diagramming Tools Diagramming Tools Repository Code Generation Code Generation Project Management Project Management Prototyping Syntax Verifiers Syntax Verifiers l What is computer-aided software engineering?
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 31 Prototyping l What is prototyping? l Object-oriented technology includes object- oriented programming (OOP) and object- oriented databases. l The goal of object-oriented programming is to make software easier to create, simpler to use, and more reliable through reusability.
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 32 Object-Oriented Technology l An objet-oriented database stores both data and the procedures that operate on the data as a single unit, that is, an object. l With object-oriented programming, common functions are defined as objects and stored in a repository. l Parent objects contain code for common functions.
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 33 Program-Change Control l Program-change controls concern the maintenance of application programs. l The objective of such controls is to prevent unauthorized and potentially fraudulent changes from being introduced into previously tested and accepted programs. l Control of program changes involves documentation and review.
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 34 Database Administration l A major control activity of the DBA is to establish standards and documentation for the data elements in a database. l Database administration must deal with the issues of data security, integrity, data sharing, recovery/backup, and audit trails.
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 35 Planning and Organizing a Systems Project l Project selection is usually the responsibility of a steering committee or other organizationwide unit to assure active user participation in the selection process. l One important task of management is to assemble a suitable project team.
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 36 Project Team Organization Information Systems Department Steering Committee User Department Analysts/ Programmers Analysts/ Programmers Lead Analysts Lead Analysts Technical Staff Technical Staff User Member User Member Project Leader Project Leader
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 37 Project Leader Responsibilities Progress and Time Reporting Allocation of Resources Status Reporting Task Assignment Activity Task/ Scheduling Project Breakdown SchedulingPlanningControl
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 38 Factoring a Project into Phases and Tasks ImplementationAnalysisDesign New System Application Study Vendor Selection Output Design Form Design Program Design Equipment Delivery Documen- tation 1.02.03.0 1.1 1.2 3.13.2 2.12.32.2
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 39 Work Measurement Techniques l The simplest approach to estimation is to guess. l More rigorous approaches to estimation are based on the concept of work measurement. 1 Identify the tasks to be estimated. 2 For each task, estimate the total size or volume of the task in some suitable manner.
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 40 Work Measurement Techniques 3 Convert the size or volume estimate into a time estimate by multiplying the size or volume estimate by a standard or estimated processing rate. 4 Adjust the estimated processing rate to include circumstantial considerations such as idle time, task complexity, or task newness.
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 41 Accuracy of Estimates l There is general agreement on several points related to the estimation process. 1 Estimates are only estimates. 2 Accuracy of estimation improves as a project proceeds through its course of activities. 3 Initial estimates are frequently made too low.
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 42 Project Accounting l A project accounting system is a cost accounting system in which costs are assigned to individual projects. l Effective project control requires a project accounting system that can keep track of costs incurred to date on a project and provide a summary cost report at a project’s completion.
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 43 Project Accounting System Computer Usage Summaries Computer Usage Summaries Project Accounting System Project Accounting System Overhead Rates Overhead Rates Cost to Date Cost to Date Progress Report Progress Report Time Sheets Time Sheets Revised Cost Estimate Revised Cost Estimate
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2001 Prentice Hall Business Publishing, Accounting Information Systems, 8/E, Bodnar/Hopwood 11 - 44 Project Accounting System Project Accounting System Project Accounting System Number 91-045 Costs Actual Budget Materials XXX XXX LaborXXXXXXXX Overhead XXX XXX Project Schedule Number 91-045 Costs Actual Budget Materials XXX XXX LaborXXXXXXXX Overhead XXX XXX Project Schedule Project File
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