In the present study, the model for the scheduling of internal audits in Boritz and Broca (1986) is extended and applied to the scheduling of financial statement audits."* In the external audit context, each company represents an auditable unit; companies are classified on a risk scale that reflects the losses that would occur in the absence of auditing; and the cost of an audit is specified as an increasing function of the audit interval. The model balances the audit cost against the losses that accrue in the absence of auditing to determine the optimal interval between audits. This study applies the scheduling model to actual data rather than hypothetical data as done in prior internal audit scheduling research (above). The data were taken from a survey of private (family-controlled) companies that had voluntarily engaged the services of an external auditor. Hence the approach has immediate application in a voluntary audit environment but we suggest it is appropriate to atiy firm notwithstanding the constraint of tbe mandatory audit rule.