Developer Data Modeling Mistakes: From Postgres to NoSQL
Ch 14
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
Florida Atlantic University
Bhattacharya, Ph.D.
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
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 14-15 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 14-15 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 14-15 Continued
15. Recurring Costs Related to a ComputerBased 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 ComputerBased 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 14-16 Continued
17. Typical Conceptual Design
Specifications - I
System Components
Output
Figure 14-17
Features
Name
Purpose
Distribution to users
Contents
General format
Frequency or trigger
Timeliness
Output medium
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 14-17 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 14-17 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 14-17 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 14-17 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
25. The Sequence in Designing
System Components
Design Controls
& Security Measures
Design
Information
Outputs
Figure 14-19
Design
data base
Design Data
Processing
Operations
Design
Data Inputs
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
Determination
of Design
Feasibility
Systems
Planning
Systems
Analysis
Systems
Design
Solicitation of
Hardware and
Software Proposals
Evaluation of
System
Proposals
Selection of
System Hardware
and Software
Systems Justification & Selection
Systems
Operations
Figure 14-21
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 14-22 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 14-22 Continued
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
Cost accounting
& control reports
Performance Evaluation Systems
* Personnel performance by
Clerks & Operators
Systems professionals
Systems managers
* Equipment performance
* Information system performance
Efficiency
Effectiveness
Performance
reports
Figure 14-27