Chapter 5
UNDERSTANDING
AND DESIGNING
ACCOUNTING DATA
Identifying and
Documenting Files
Transaction files:
 Used to record
information about events
in a business process
Identifying and
Documenting Files
Transaction files:
 Attributes include:
 Transaction date
 Agents associated with
transaction
 Description of
products/services
associated with event
Identifying and
Documenting Files
Master files:
 Store reference data
 Store summary data
Identifying and
Documenting Files
Events and transaction files:
 First, identify the events in
the business process
 Then, identify the need for
transaction files in the AIS
Documenting
Transaction Files
UML class diagram:
 Shows relationships
between transaction
and master files
 Each box represents a
file
 Connecting lines
between files indicate
file relationships
Documenting
Transaction Files

UML class diagram:
Can be used to document:
 Tables in an AIS
 Relationships between
tables
 Attributes of tables
Documenting
Transaction Files
Guidelines for identifying
need for transaction
tables:
1: Determine the events in
the process
2: Exclude events that do
not need to be recorded
in the computer system
Documenting
Transaction Files
Guidelines for identifying
need for transaction
tables:
3: Exclude query and
reporting events because
they involve using data
that have already been
recorded in the AIS
4: Exclude maintenance
events
Documenting
Transaction Files
Events and master tables:
 Typical master tables:
 Products/services - master
tables
 Describe
products/services offered
 Identify costs and/or
prices of
products/services
 Agents - master tables
describe
 External agents
 Internal agents
Documenting
Transaction Files
Events and master tables:

Typical master tables
 Cash - master file
describes where cash is
stored
 General ledger master file
- needed if general ledger
system is
 Automated and
 Integrated with the
revenue or acquisition
cycle
Documenting
Transaction Files
Events and master tables:
 Generally, master tables
are used to store
relatively permanent data
about an entity
Documenting
Transaction Files
Benefits of master tables:

Save data entry time

Save storage space


Simplify making changes
to data
Simplify deleting
transaction records
Attributes and
Relationships
3 important concepts
 Primary keys
 Linking attributes
(foreign keys)
 Relationship
cardinalities
Attributes and
Relationships
Primary key:
 Attribute(s) that uniquely
identifies a record in a table
Attributes and
Relationships
Foreign key:
 A field in a table that is
the primary key in some
other table
 Used to link one table to
another
 Link event records to
master records
 Link two events that
occur in a sequence
Attributes and
Relationships
Cardinality of the relationship:
(covered in the text)



One-to-one relationships
(1,1) - not nearly as common
as one-to-many relationships
One-to-many relationships
(1,m) - common in
accounting systems
Many-to-many relationships
(m,m) - can be converted
into two one-to-many
relationships by adding a
“junction table”
Attributes and
Relationships
Cardinality of the relationship:
 Important in designing a
database
 Represents how many
occurrences of one type of
entity are associated with
another type of entity
Attributes and
Relationships

Significance of concepts
for database applications:
Implementing documents
and reports
Attributes and
Relationships

Significance of concepts for
database applications:
Implementing input forms
 Input forms are used to
make data entry more
accurate/efficient
 Form designs rely on
primary and foreign keys
and relationships
between tables
Attributes and
Relationships

Significance of concepts for
database applications:
Controlling AIS data –
referential integrity
 For one-to-many
relationships
 Can specify if want
referential integrity
enforced on relationship
 Control most effective
with two other controls:
 Segregation of duties
and
 Access controls
Designing Data with
a UML Class Diagram

Developing a data design
using a UML class diagram:
Four basic steps
Step 1: Place the required
transaction tables (files)
on the UML class diagram.
 Identify events in a
business process.
 Decide which events will
need transaction tables.
 Start the UML class
diagram by showing a box
for each event requiring
transaction tables.
Designing Data with
a UML Class Diagram

Developing a data design
using a UML class diagram:
Four basic steps
Step 2: Place required
master tables (files) on
UML class diagram
 For each event on the
diagram (from Step 1),
determine related goods,
services, or agent entities
 Determine which
identified entities require
master tables
Designing Data with
a UML Class Diagram

Developing a data design
using a UML class diagram:
Four basic steps
Step 2 (continued):
 Consider using master
tables to track location of
cash and effect of events
on account balances in
the general ledger
 Add required master
tables to appropriate side
of the UML class diagram
Designing Data with
a UML Class Diagram

Developing a data design
using a UML class
diagram:
Four basic steps
Step 3: Determine
required relationship
between tables
 For each connecting
lines, determine
cardinality of the
relationship between
tables
Designing Data with
a UML Class Diagram

Developing a data design
using a UML class diagram:
Four basic steps
Step 3 (continued):
 Write cardinalities next to
line between entities
 If there are any many-tomany relationships,
convert them to one-tomany relationships by
adding junction table
Designing Data with
a UML Class Diagram

Developing a data design
using a UML class diagram:
Four basic steps
Step 4: Determine required
attributes by:
 Assigning a primary key to
each tables
 Linking related tables by
adding a foreign key to one
of the pair in the
relationship
 Linkage depends on
cardinality of the
relationship
Designing Data with
a UML Class Diagram

Additional data design
implementation issues:
Suggestions
 One master table instead
of two
 One event table instead of
two
 Option A: Two records in
two tables
 Option B: One record in
one table
 Eliminate redundant
relationships
 Add relationships not
involving event records
Designing Data with
a UML Class Diagram

Communicating
the data design:
Guidelines in preparing
documentation
 Be consistent in naming
entities
 Name boxes so can easily
correlate UML diagram
with preceding
documentation
 Help reader understand
how each part of the
documentation relates to
other parts
Designing Data with
a UML Class Diagram

Communicating
the data design:
Guidelines in preparing
documentation Proper layout can also
enhance readability
 Start each part on a
separate page
 Clearly label each part
 Write a brief explanation of
the information obtainable
by reviewing diagram
 Use bulleted lists to explain
linkages between diagrams
 Use same style throughout
Keyterms

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Attributes
Cardinality
Database
Database management
system
Foreign key
Primary key
Referential integrity
Relational database
UML class diagram