1. Chapter 5 UNDERSTANDING AND DESIGNING ACCOUNTING DATA

2. Identifying and Documenting Files Transaction files: Used to record information about events in a business process

3. Identifying and Documenting Files Transaction files: Attributes include: Transaction date Agents associated with transaction Description of products/services associated with event

4. Identifying and Documenting Files Master files: Store reference data Store summary data

5. 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

6. 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

7. Documenting Transaction Files UML class diagram: Can be used to document: Tables in an AIS Relationships between tables Attributes of tables

8. 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

9. 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

10. 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

11. 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

12. Documenting Transaction Files Events and master tables: Generally, master tables are used to store relatively permanent data about an entity

13. Documenting Transaction Files Benefits of master tables: Save data entry time Save storage space Simplify making changes to data Simplify deleting transaction records

14. Attributes and Relationships 3 important concepts Primary keys Linking attributes (foreign keys) Relationship cardinalities

15. Attributes and Relationships Primary key: Attribute(s) that uniquely identifies a record in a table

16. 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

17. 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”

18. 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

19. Attributes and Relationships Significance of concepts for database applications: Implementing documents and reports

20. 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

21. 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

22. 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.

23. 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

24. 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

25. 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

26. 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-to- many relationships, convert them to one-to- many relationships by adding junction table

27. 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

28. 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

29. 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

30. 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

31. Keyterms Attributes Cardinality Database Database management system Foreign key Primary key Referential integrity Relational database UML class diagram