Chapter 14: Systems Development

Transcription

1 Accounting Information Systems: Essential Concepts and Applications Fourth Edition by Wilkinson, Cerullo, Raval, and Wong-On-Wing Chapter 14: Systems Development Slides Authored by Somnath Bhattacharya, Ph.D. Florida Atlantic University

2 Interaction of Systems Development with Accounting 1) Assigning both the controller and the information systems manager to the steering committee 2) Assigning accountants to systems project teams 3) Assigning persons who are knowledgeable in both accounting and information technology to serve as coordinators between the accounting and information systems functions 4) Establishing an internal audit group, staffed by accountants and systems-oriented auditors 5) Establishing data control groups within accounting departments

3 Approaches to Systems Development Top-Down versus Bottom-up In-House versus Outsourcing Re-engineering Prototyping

4 Objectives of Strategic Systems Planning Integrate the information system development with the firm s overall planning processes Ensure orderly development of systems projects, making efficient use of available resources Recognize changing priorities and newly arising conditions as well as increasing informational demands Incorporate improvements in information technology as they become relevant to the firm s needs and promise greater benefits than the cost outlays

5 Survey of the Present System Scope Data Types and Sources Behavioral Issues Communicate openly with the persons to be affected by the system project Encourage participation by the affected persons throughout the survey Emphasize the positive aspects of the project and explain that the resulting system can better meet the users needs Reduce the fears of employees and managers by establishing and publicizing fair personnel policies

6 A Checklist for Analyzing Information Systems - I Are tasks and responsibilities clearly defined and assigned? Are tasks and responsibilities distributed effectively among employees and organizational units? Are the policies and procedures understood and followed? Does the productivity of the clerical employees appear to be satisfactorily high? Do the various organizational units cooperate and coordinate well in maintaining smooth flows of data? Figure 14-8

7 A Checklist for Analyzing Information Systems - II Does each product achieve its intended objective? Are redundant processing operations being performed? How necessary is the result accomplished by each operation? Do unnecessary delays occur in obtaining and/or processing data? Do any operations cause bottlenecks in the flow of data? Are the number of errors that occur in each operation minimized? Figure 14-8 Continued

8 A Checklist for Analyzing Information Systems - III Are physical operations adequately planned and controlled? Is the capacity of the information system sufficient to handle the average volumes of data without large backlogs? Are the peak volumes of data handled adequately? How easily does the system adapt to exceptional occurrences and growth in use? How necessary is each document? Is each document suitably designed for efficient use? Figure 14-8 Continued

9 A Checklist for Analyzing Information Systems - IV Are all copies of documents necessary? Can reports be prepared easily from the files and documents? Does unnecessary duplication occur in files, records, and reports? Are files easily accessible and kept up-to-date? Are sound performance standards developed and kept up-to-date? Is data processing equipment being used effectively? Is the system of internal control adequate? Do the informal flows of data and information harmonize with the formal flows? Figure 14-8 Continued

10 A List of Information Systems Capabilities Efficient and hence economical operations Adequate capacity for expected growth Timeliness in responding to inquiries and providing reports Reliability of system hardware and software Accurate, up-to-date, and relevant information Security of the data and system facilities Flexibility and adaptability to changes and new demands Simplicity, and hence user-friendliness Figure 14-9

11 One-time Costs for a New or Improved Computer-based Information System - I System Design Costs Detailed design Programming System Installation and Conversion Costs System and program testing File conversion Retraining of displaced employees Training of newly hired analysts, programmers, and operators Inefficiencies caused by learning new equipment and procedures Figure 14-15

12 One-time Costs for a New or Improved Computer-based Information System - II System Site Preparation Costs Construction of wiring and piping systems Construction of electrical power supply Construction of air-conditioning system Construction of sprinkler system Construction of other miscellaneous facilities, such as false flooring, file storage vault, and special lighting Figure Continued

13 One-time Costs for a New or Improved Computer-based Information System - III System Hardware Costs Central processing unit Additional processors Secondary storage devices Input-output devices Data communications equipment Terminals Peripheral equipment, such as key-to-disk devices Transportation of equipment Figure Continued

14 One-time Costs for a New or Improved Computer-based Information System - IV System Software Costs Operating system, utility routines, compilers Data communications software Application program packages Data management software packages Decision model software packages Outside computer time-sharing rentals Figure Continued

15 Recurring Costs Related to a Computer- Based Information System - I Computer Operations Costs Salaries for computer supervisors, operators, technicians, data-entry clerks, librarians, security guards, and others Supplies, including forms, paper, ribbons, and tape Utilities, including power, water, and telephone Rentals of computer hardware Software purchases and upgrades Communications equipment and services Backup equipment and services Figure 14-16

16 Recurring Costs Related to a Computer- Based Information System - II Information System Maintenance Costs Salaries for systems analysts, programmers, repair technicians, and others Replacement parts and upgrades Printing costs for documentation Information System Administration Costs Salaries of systems management, data-base administrator, internal auditors, secretaries, and others Insurance Taxes Space and building occupancy costs Figure Continued

17 Typical Conceptual Design Specifications - I System Components Output Features Name Purpose Distribution to users Contents General format Frequency or trigger Timeliness Output medium Figure 14-17

18 Typical Conceptual Design Specifications - II System Components Data base Features File or table name File or table type File size Contents of record or table Record or table layout File organization method Storage medium Data characteristics Updating frequency Figure Continued Data structure

19 Typical Conceptual Design Specifications - III System Components Data processing Features Sequence of steps or runs Processing modes, cycles, volumes Modes of data communication Processing capabilities at each physical location Figure Continued

20 Typical Conceptual Design Specifications - IV System Components Data input Features Name Purpose Source Method of collecting data Volume (peak and average) Contents (data elements) General format Figure Continued Data entry method

21 Typical Conceptual Design Specifications - V System Components Control and security Features Type Purpose Specific system components affected method of correcting error or establishing security Figure Continued

22 Systems Acquisition Options Purchasing versus leasing Single vendors versus multiple vendors In-house system versus outsourcing computing services In-house software development versus commercial software packages Types of commercial software General accounting systems Turnkey software systems

23 Advantages of Commercial Software Products available without lengthy developmental periods Soundly designed and well-tested and thus efficient and reliable Reasonable pricing

24 Limitations of Commercial Software Generalized in nature Acquiring firm is dependent on the software vendor for support and maintenance and upgrades

25 The Sequence in Designing System Components Design Controls & Security Measures Design Information Outputs Design data base Design Data Processing Operations Design Data Inputs Figure 14-19

26 A List of Design Principles Foster system objectives Incorporate reasonable tradeoffs Focus on functional requirements Serve multiple purposes Relate to users concerns Provide a tailored product Integrate system modules and components Avoid design excesses Apply sound methodology Figure 14-20

27 System Justification & Selection in the Systems Development Life Cycle Systems Planning Determination of Design Feasibility Solicitation of Hardware and Software Proposals Systems Analysis Evaluation of System Proposals Systems Design Selection of System Hardware and Software Figure Systems Justification & Selection Systems Operations

28 A List of Resource Specifications - I Systems Design Specifications Output Data-base Processing Input Control & security Figure 14-22

29 A List of Resource Specifications - II Hardware Specifications Processor speeds and capabilities Secondary storage capacities and access capabilities Input-output speeds and capabilities Compatibility features Modularity features Error detection and correction techniques Data communication capabilities Special features, such as multiprogramming and virtual storage maximum allowable downtime as a percentage of total time Figure Continued

30 A List of Resource Specifications - III Software Specifications Programming languages and compilers Utility packages Application packages Operating system capabilities Data management packages System Support Specifications Programming assistance Training programs Test facilities and time available Backup facilities Maintenance assistance Figure Continued

31 Techniques for Proposal Evaluation The benchmark problem technique Simulation model technique Weighted-Rating analysis technique

32 Systems Implementation: Preliminary Actions Establish implementation plans and controls Gantt chart Network diagrams Recognize behavioral concerns Review the organization of the project team Complete arrangement for selected system resources

33 Implementation Activities - I Personnel selection and training Physical site preparation Detailed system design Output design Database design Input design Processing design Controls design

34 Implementation Activities - II Application software development Coding Structured programming Software testing Desk checking String testing System testing Acceptance testing

35 Implementation Activities - III Standards development System components Performance Documentation Documentation File conversion

36 Implementation Activities - IV System conversion: cutover Direct conversion approach Parallel operation approach Modular conversion approach Phased conversion approach User signoff

37 Systems Operations Fine tuning Post-implementation evaluation To assess the degree to which the objectives of the system project have been met To spot any additional modifications that might be needed in the newly designed system To evaluate the project team s performance, both in terms of a quality product and adherence to the project schedule and work plan To serve as the basis for improving future systems developments and accuracy of cost and benefit estimates

38 A Framework Pertaining to the Control of System-Related Resources Measurement of Resource Usage * Personnel Time Reporting Systems * Computer-oriented Monitoring Systems * Effectiveness Monitoring Systems Chargeback Systems * Chargeback Rates * Usage Measurements by Department Task Project Computer System Performance Evaluation Systems * Personnel performance by Clerks & Operators Systems professionals Systems managers * Equipment performance * Information system performance Efficiency Effectiveness Cost accounting & control reports Performance reports Figure 14-27

39 Accounting Information Systems: Essential Concepts and Applications Fourth Edition by Wilkinson, Cerullo, Raval, and Wong-On-Wing Copyright 2000 John Wiley & Sons, Inc. All rights reserved. Reproduction or translation of this work beyond that permitted in Section 117 of the 1976 United States Copyright Act without the express written permission of the copyright owner is unlawful. Request for further information should be addressed to the Permissions Department, John Wiley & Sons, Inc. The purchaser may make back-up copies for his/her own use only and not for distribution or resale. The publisher assumes no responsibility for errors, omissions, or damages, caused by the use of these programs or from the use of the information contained herein.