THE SCHEDULE OF ECONOMIC LOT SIZES,
Abstract
A general model was developed for the sequencing of lot sizes through a single machine for the case of deterministic demand at a constant rate for each of several products and under the situation in which the changeover time on the machine is dependent upon the sequencing of products. The problem was shown to be one of minimizing a quadratic criterion function subject to linear restraints over the possible cycles (sequences) of production. Even extremely simplified versions of the problem reduced to problems whose solutions still defy operational analysts. In an attempt to study the problem experimentally rather than analytically it was proposed that the rather cumbersome parameter, the changeover matrix, be characterized as a linear combination of certain extreme changeover matrices, whose effect on policy might be determined analytically. For the case of a changeover matrix with equal entries (Equal Entry) it was shown that demand variability over products had to be rather high in order to justify other than a strict sequencing of the products through the machine (rotation cycle). Also in the case of the Equal Entry changeover matrix it was established that a cycle whose length is one more than the number of products must be a rotation cycle, but that the result does not hold when the cycle length is two more than the number of products. In the case of the Come-Down changeover matrix and the Proportional Come-Down changeover matrix the nature of the best cycle was established.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1964
- Accession Number
- AD0622080
Entities
People
- William L. Maxwell
Organizations
- Cornell University College of Engineering