We modify the likelihood-based method for obtaining derivatives with respect to the rate of a Poisson process to that it is not necessary to know the exact value of that rate. This type of modification is necessary if the method is to be used on a sample path from a real system. The method is...

The familiar square-root formula for the optimal economic order quantity was derived originally by Harris in 1915 (Harris, F. W. 1915. What quantity to make at once. The Library of Factory Management, Vol. V. Operation and Costs. A. W. Shaw Company, Chicago, 47--52.). Since all citations found...