database model merely permits integration to occur; integration is not guaranteed. Poor systems design can occur under any model. In fact, most organizations today that employ a relational database run applications that are traditional in design and do not make full use of relational technology. The two remaining models to be discussed (REA and ERP) employ relational database technology more effectively.
The REA Model
REA is an accounting framework for modeling an organization’s critical resources , events, and agents (REA) and the relationships between them. Once specified, both accounting and nonaccounting data about these phenomena can be identified, captured, and stored in a relational database. From this repository, user views can be constructed that meet the needs of all users in the organization. The availability of multiple views allows flexible use of transaction data and permits the development of accounting information systems that promote, rather than inhibit, integration. The REA model was proposed in 1982 as a theoretical model for accounting.2 Advances in database technology have focused renewed attention on REA as a practical alternative to the classical accounting framework. The following summarizes the key elements of the REA models.
Resources
Economic resources are the assets of the organization. They are defined as objects that are both scarce and under the control of the enterprise. This definition departs from the traditional model because it does not include AR. An account receivable is an artifact record used simply to store and transmit data. Because it is not an essential element of the system, it need not be included in the database. Instead, AR values are derived from the difference between sales to customers and the cash received in payment of sales.
Events
Economic events are phenomena that affect changes in resources. They can result from activities such as production, exchange, consumption, and distribution. Economic events are the critical information elements of the accounting system and should be captured in a highly detailed form to provide a rich database.
Agents
Economic agents are individuals and departments that participate in an economic event. They are parties both inside and outside the organization with discretionary power to use or dispose of economic resources. Examples of agents include sales clerks, production workers, shipping clerks, customers, and vendors. The REA model requires that accounting phenomena be characterized in a manner consistent with the development of multiple user views. Business data must not be preformatted or artificially constrained and should reflect all relevant aspects of the underlying economic events. As such, REA procedures and databases are structured around events rather than accounting artifacts such as journals, ledgers, charts of accounts, and doubleentry accounting. Under the REA model, business organizations prepare financial statements directly from the event database. The following sales and cash receipts events for
2
W. E. McCarthy, “The REA Accounting Model: A Generalized Framework for Accounting Systems in a Shared Data Environment.” The Accounting Review (July 1982): 554–57.