CAPEX: A Knowledge-Based Expert System for Substantive Audit Planning

CAPEX (Canadian Audit Planning Expert System) is a knowledge-based system designed to generate substantive audit program plans using an assertion-based risk-oriented approach to structuring audit objectives and the assessment of audit evidence. This type of approach is advocated by major professional accounting bodies and used by an increasing number of major audit firms both in North America and around the world.

The book provides an overview of CAPEX, including the user interface and key outputs, addresses the knowledge acquisition process, knowledge representation, system validation, lessons learned, system limitations, and suggestions for future research, as well as including various appendixes, figures, tables, and references.

To generate an audit program CAPEX uses an extensive body of encoded knowledge about audit evidence-gathering, using both tests of detail and analytical procedures. In its present implementation, CAPEX can generate audits for revenue, receipts, and receivable cycles for banking, retail, and manufacturing clients, as well as inventory, purchases, payables, and costs of sales cycles for manufacturing clients.

CAPEX (Canadian Audit Planning Expert System) has been validated using a variety of cases developed by experienced auditors from both Canada and the United States.

It was developed using Prolog, X-Windows and C in a Unix environment.


J. Efrim Boritz is an associate professor of Accounting at the University of Waterloo, Ontario.

Anthony K.P. Wensley is an assistant professor at the University of Toronto.