A Study of the Total Inventory Cost as a Function of the Reorder
Interval of Some Lot-Sizing Techniques Used in
Material Requirements Planning Systems
J. of Computers and Industrial Engineering,
Vol. 40, No. 1-2, pp. 101-116, (2001).
S. Nieto Sanchez, E. Triantaphyllou, D.B. Webster, and
This paper compares the total inventory costs (TIC) of five lot-sizing techniques.
The add-drop heuristic (ADH) is a capacitated technique and the lot-for-lot (L4L),
fixed period quantity (FPQ); least unit cost (LUC) and the silver-meal heuristic (SMH)
are uncapacitated techniques. The TIC is considered as a function of the reorder interval (RI).
This comparison is based on the assumption that if both capacitated and uncapacitated techniques
produce identical RIs, then their TICs must also be identical (although uncapacitated techniques
do not reflect this fact). Empirical results suggest that the ADH techniques yields considerably
better (i.e. lower) TIC's when the levels and the number of items are low. On the other hand,
these results suggest that for high demand levels, the TICs of the four popular lot-sizing techniques
are close to the near optimal cost obtained by the (most time-consuming) ADH technique. Some
theoretical results on the performance of the uncapacitated techniques are also presented.