| Several sources in professional accounting have acknowledged the need for structured models for the analysis and evaluation of the accounting control systems. This study presents a framework for a decision support system (based on reliability engineering concepts) for the assessment, design, and maintenance of the reliability of the accounting control systems. This framework includes: (1) A reliability assessment model that provides a quantitative (probabilistic) measure of the error rate in the system, (2) A dynamic programming model which identifies different possible designs of number and location of controls to be placed in the system such that a range of acceptable error rates and corresponding total costs of the system is defined, and (3) Two practical models that could be used in designing the inspection/maintenance (audit) schedule for the accounting control systems. A computer program has been developed for the application of the dynamic programming model. Applications of these models to two hypothetical system examples have revealed the following: (1) Adding a control component to the system does not necessarily decrease its reliability, (2) The points at which branches merge or diverge in the system are good candidates for placing controls, (3) Placing controls early in the system would decrease its total cost while placing them close to the end of the system would reduce the error rate in the outputs, and (4) An optional schedule for investigating the performance of the accounting control system does not necessarily suggest an equal spacing of audits over time. |
