Many manufacturing firms produce component parts both for assembly into new products and to meet orders for spare parts. An inventory model for this situation would involve two types of demands: probabilistic demand as spares and deterministic (or scheduled) withdrawals as components for...

Operations management (OM) and human resources management (HRM) historically have been very separate fields. In practice, operations managers and human resource managers interact primarily on administrative issues regarding payroll and other matters. In academia, the two subjects are studied by...

Worksharing occurs in serial manufacturing when machines are not uniquely assigned to workers. For example, two workers can operate three machines by alternating usage of the middle one. In some other worksharing systems operators move down the line carrying an item (or batch) with them, working...

Order crossover occurs whenever replenishment orders do not arrive in the sequence in which they were placed. This paper argues that order crossover is becoming more prevalent and analyzes the dangers of ignoring it. We present an exact iterative algorithm for computing the distribution of the...

In this paper we present a heuristic method, based on Lagrangian relaxation, for multilevel lot-sizing when there is a single bottleneck facility. A series of Lagrangian relaxations (one for each item in the product structure) is imbedded in a branch and bound procedure. The objective is to find...

In this Note we present an alternative formulation to the MRP lot sizing model of Steinberg and Napier (SN) (Steinberg, E., H. A. Napier. 1980. Optimal multi-level lot sizing for requirements planning systems. Management Sci. 26 (2) 1258--1271.). The alternative is more parsimonious and the...

In this Note, we address the issue of safety stock considerations in an MRP environment through the use of a single identical component as a replacement for a set of multiple components. We indicate where the results reported by Collier (Collier, David A. 1982. Aggregate safety stock levels and...

Customer service has assumed strategic importance in most manufacturing environments. Corporate reputations often depend on how reliably promised lead times are met. A goal of filling orders within a service window of T time units is often encountered in practice. This goal ignores the...

This paper introduces a line of research on capacity-constrained multi-stage production scheduling problems. The first section introduces the problem area as it arises from a failure of MRP systems. Then a review of the literature and an analysis of the type of problems that exist are presented...