Core Concepts of Accounting Information Systems, 13th Edition, by Simkin, Rose, and Norman
SM 7.1
Chapter 7
DATA MODELING
Discussion Questions
7-1. Almost every AIS must organize and store data in permanent files. This leads to the
need for databases that help business and governmental users store, modify, extract, and
networks, (4) the need for privacy and security, (5) the fact that most AIS databases contain
irreplaceable data, (6) the importance of accuracy, and (7) Internet uses such as storing online
detail.
7-2. The hierarchy of data describes the fact that AISs store the data in a database in
data field → record → file → database
Examples will vary for each student.
7-3. The data field in each record that uniquely distinguishes one record from another on a
computer file is called the primary key. Typically, the primary key is numeric, although
AIS databases also use foreign record keys to link the records in one database table to the records
7-4. Here are some examples of typical accounting information system files and the
potential record keys used for each:
Computer File Potential Record Key
Accounts Receivable Master File Customer account number
Purchase Order File Invoice number
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Inventory File Inventory Part number
Check-Writing File Check number
Transaction File Account number and date
7-5. The data in large, commercial databases pose special challenges for database
designers and users. Some major concerns are:
are performed properly and completely
(3) concurrency: ensuring that two users do not access and sequentially change the same
database record at the same time
fraudulent manipulation.
Specific examples will vary by students.
7-6. The term “REA” is an acronym for “resources, events, and agents.” In the REA
resources, events, or agents that do not immediately affect the financial statements of a company.
competitor activities.
7-7. Database cardinalities represent the relationships between database entities—for
“employees” and “pay rates.”
7-8. The entity-relationship (E-R) model is a graphic tool for helping developers design
7-9. Assuming that the records in the Salesperson table stores information about
individual sales people (e.g., name, employee number, office phone number, etc.) and that the
any given month, you would need to create a relationship between them to link the file records in
these two tables together. The use of foreign keys would be sufficient to do this, and you would
Core Concepts of Accounting Information Systems, 13th Edition, by Simkin, Rose, and Norman
SM 7.3
modeling are important—if challenging—topics in AIS.
7-10. Normalization is a process for ensuring that attributes are stored in the most
appropriate tables and are non-redundant. The text describes the first three levels of
updating data.
Problems
7-11.
a) Definitions:
1) Field: A set of characters that describe or define a particular file entity, (e.g., the
employee number field in a payroll file).
an employee in a payroll file).
3) File: A collection of records about similar file entities, (e.g., a collection of employee
records in a payroll file).
b) 1) A database is a collection of data files that are shared by one or more accounting
2) Database advantages:
a) Eliminates or reduces data redundancy
b) Reduces data conflicts that often result from files of duplicate information
c) Centralizes file information
d) Separates file data from the applications that use them, enabling the application to
Disadvantages:
a) Increases work of creating and maintaining databases
b) Increases coordination among the data needs of several departments requiring, or
collecting, the data in the database
c) Increases the need for security to protect informational assets
e) Increases cost
Core Concepts of Accounting Information Systems, 13th Edition, by Simkin, Rose, and Norman
SM 7.4
7-12. Data items likely to be included in a cash table are: Cash Account #, Type of
The Cash Receipts table would include: Cash Receipt #, [Cash Account #], Date Received,
foreign keys.
7-13.
surgeries. A doctor can perform zero to many surgeries. A nurse can perform zero to many
surgeries.
7-14.
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7-15.
7-16. Here are some potential data fields for a Customer Table:
Data field
Data type
Suggested Size
Customer Number
Text
4
Last Name
Text
30
First Name
Text
20
Street Address
Text
30
City
Text
20
State Abbreviation
Text
2
Zip Code
Numeric
5 (or 9 digits)
Credit Limit
Numeric
7 (long integer)
7-17. Customer #, customer name, customer address, customer phone
Child #, child name, [customer #]
7-18. Student #, student name, student address, student phone
Class #, class time, class room
[Student#], [Class#], grade
7-19. Bonadio Electrical Supplies company.
a. The basic differences between a file-oriented system and a database management system
(DBMS) include:
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1) The file-oriented system focuses on individual applications, each with its own set of files
and with each file physically separate from the other files
2) In the database management system, the focus is on data rather than on a particular
data security, and shared data ownership
3) The records in files typically are organized in only one way—for example, sequentially
according to some key or chronologically. The records in databases are typically
b. Advantages of database management systems:
1) Reduced data redundancy and inconsistencies
3) Single data entry and shared information
4) Data accessibility increases the timeliness, effectiveness, and availability of information
Disadvantages of database management systems:
1) Typically more difficult to create initially
2) More highly trained technical personnel are required
files and applications.)
4) Audit trails being somewhat obscured as the result of multiple users and perhaps multiple
copies of the same database
c. The duties and responsibilities of the database administrator include:
independence and back-up and recovery procedures.)
2) Definition and control of the data dictionary
Case Analyses
7-20. Ian’s Place (Planning a Database Using REA and E-R Diagrams)
1. The resources are cash and inventory. The events are sales orders, shipping goods, and cash