LINE SEARCH TECHNIQUES FOR THE LOGARITHMIC BARRIER FUNCTION IN QUADRATIC-PROGRAMMING

In this paper, we propose a line-search procedure for the logarithmic barrier function in the context of an interior point algorithm for convex quadratic programming. Preliminary testing shows that the proposed procedure is superior to some other linesearch methods developed specifically for the logarithmic barrier function in the literature

Integrated Production Maintenance And Quality Model For Imperfect Processes

In this paper, we develop an integrated model for the joint optimization of the economic production quantity, the economic design of (x) over bar-control chart, and the optimal maintenance level. This is done for a deteriorating process where the incontrol period follows a general probability distribution with increasing hazard rate. In the proposed model, Preventive Maintenance (PM) activities reduce the shift rate to the out-of-control state proportional to the PM level. Compared to the case with no PM, the extra cost of maintenance results in lower quality control cost which may lead to lower overall expected cost. These issues are illustrated using an example of a Weibull shock model with an increasing hazard rate

LINE SEARCH TECHNIQUES FOR THE LOGARITHMIC BARRIER FUNCTION IN QUADRATIC-PROGRAMMING

In this paper, we propose a line-search procedure for the logarithmic barrier function in the context of an interior point algorithm for convex quadratic programming. Preliminary testing shows that the proposed procedure is superior to some other linesearch methods developed specifically for the logarithmic barrier function in the literature

Integrated Production And Quality Model Under Various Preventive Maintenance Policies

In this paper, we investigate the effect of various preventive maintenance policies on the joint optimisation of the economic production quantity (EPQ) and the economic design of control chart. This has been done for a deteriorating process where the incontrol period follows a general probability distribution with increasing hazard rate. In the proposed model, preventive maintenance (PM) activities reduce the shift rate of the system to the out-of-control state proportional to the PM level. For each policy, the model determines the EPQ, the optimal design of the control chart and the optimal preventive maintenance level. The effects of the three PM policies on EPQ and quality costs are illustrated using an example of a Weibull shock model with an increasing hazard rate

Effect Of Maintenance On The Economic Design Of (X)Over- Bar-Control Chart

An integrated model for the joint optimization of the maintenance level and the economic design of x-control chart is presented. This is done for a deteriorating process where the in-control period follows a general probability distribution with an increasing hazard rate. In the proposed model, preventive maintenance reduces the shift rate to an out-of-control state by an amount proportional to the preventive maintenance level. An example of a Weibull shock model with increasing hazard rate is used to illustrate the effect of the maintenance level on quality control costs. A comparison between uniform and non-uniform schemes is made both with and without preventive maintenance. Effect of distribution parameters has also been investigated. (C) 2000 Elsevier Science B.V. All rights reserved

Optimal Lot-Sizing, Quality Improvement And Inspection Errors For Multistage Production Systems

We develop multistage lot-sizing models for imperfect production processes. The effect of inspection errors in screening non-conforming items at various stages has been incorporated. Inspection and restorstion of the processes at all stages have also been considered. Numerical examples are presented to illustrate various aspects of the models developed. It is shown that when inspection and restoration are introduced, lower costs are incurred and larger lot sizes are produced because of reductions in quality control costs

Effect Of Inspection Errors And Preventive Maintenance On A Two-Stage Production Inventory System

The effect of imperfect production processes on lot-sizing decisions has received a lot of attention in the literature. These efforts have mostly been confined to single-stage production systems. The issue of imperfect production processes has not been adequately addressed in the context of multistage production/inventory systems. In this paper, we propose a production inventory model that takes into account the effect of imperfect production processes, preventive maintenance and inspection errors. Numerical examples are presented for illustrative purposes