In the paper an approach to the analysis of business process efficiency is proposed. A method for the estimation of a business process execution time as an important performance measure of business processes efficiency is developed. It represents a combination of queuing networks modelling and simplex algorithm of linear programming. The method allows the calculating of the minimum business processes execution time. A method of optimizing activity of the telecommunication company at a predetermined threshold for the business processes execution time is given. The developed technique was illustrated with an end-to-end business process flow “Request-to-Answer” with initial data close to reality. © Springer International Publishing Switzerland 2016.