Traditional Lot Quality Assurance Sampling (LQAS) methods require random sampling to guarantee valid results. However, cluster sampling has been proposed to reduce the number of random starting points. This study uses simulations to examine the classification error of two such designs, a 67x3 (67 clusters of 3 observations) and a 33x6 (33 clusters of 6 observations) sampling scheme to assess th...

BACKGROUND Data collection techniques that routinely provide health system information at the local level are in demand and needed. LQAS is intended for use by local health teams to collect data at the district and sub-district levels. Our question is whether local health staff produce biased results as they are responsible for implementing the programs they also assess. METHODS This test-ret...

It is now widely accepted that both large and small lot sizes can cause long lead times and consequently bad customer service in terms of late deliveries. The impact of the lot size on the lead time consists of a convex relationship, implying an optimal lot size minimising average lead time. In order to educate people with this undoubtedly correct, but yet controversial issue, we developed an e...

This paper presents a simple algebraic approach for deriving the optimal lot size for economic production quantity (EPQ) model with rework process. Conventional methods for solving lot size problems are by using differential calculus on the long-run average production-inventory cost function with the need to prove optimality first. A few recent articles proposed the algebraic approach to the so...

This paper addresses the common cycle multi-product lot-scheduling problem in flexible flow lines (FFL) where the product demands are deterministic and constant over a finite planning horizon. Objective is minimizing the sum of setup costs, work-in-process and final products inventory holding costs per time unite while satisfying the demands without backlogging. This problem consists of a combi...

Wafer fabrication is a capital-intensive and highly complex manufacturing process. In a wafer fabrication facility (fab), wafers are grouped as a lot to go through repeated sequences of operations to build circuitry. Lot scheduling is an important task for manufacturers in order to improve production efficiency and satisfy customers’ demands of on-time delivery. Cycle time and average work-in-p...

Wafer fabrication is a capital-intensive and highly complex manufacturing process. In a wafer fabrication facility (fab), wafers are grouped as a lot to go through repeated sequences of operations to build circuitry. Lot scheduling is an important task for manufacturers in order to improve production efficiency and satisfy customers’ demands of on-time delivery. Cycle time and average work-in-p...

In a typical purchasing situation, the issues of price, lot sizing, etc, usually are settled through negotiations between the purchaser and the vendor. Depending on the existing balance of power, the end result of such a bargaining process may be a near-optimal or optimal ordering policy for one of the parties (placing the other in a position of significant disadvantage) or, sometimes, inoptima...