A Model for Randomized Unannounced Inspections at Any Time

A general model of randomized inspections for unannounced inspections at any time is proposed. The model is designed to satisfy the inspection criteria including both timeliness and detection probability goals. In addition, the inspection effectiveness is enhanced since inspections may commence at any time. The model does not require changes in the concept of timeliness or the use of "average " detection time. Possible significant savings in inspection resources arisingfrom the application of the model are estimated. While the paper is written in the IAEA context, the model is more general and is applicable to a much wider class of inspections.