The functional relationship between the lot size and the degree of extension of the
technological cycle time is rather obscure and can only be approximated. The ratio (r)
of the manufacturing and technological cycle times can be established, either by
analysis or by using a statistical survey. While this requires an estimate of Q before the
EPQ is established, the error of the estimate has little effect on the costs. Eilon [3]
emphasizes that the cost model is quite insensitive and that the optimal region is
represented by a flat section of the cost curve. Even if one assumes that the lengthening