Improvemert of the Method for Calculating Reserves of a Spare Parts, Tools and Accessories System

In the article we describe improvement of the method for optimal reserves calculating of a two-level spare parts, tools and accessories system that consist of one spare parts, tools and accessories group package and some spare parts, tools and accessories local packages. It is reasoned that the existing method has systematic error in itself, and we suggest a modification of the method. Modified and unmodified method are both applied for the same data, and we can see difference in results.