An integrated approach to the facilities and material handling system design

The facility layout problem involves the optimal location of manufacturing facilities into a workshop. The classical approach to the layout design is carried out in two separate steps: the first step is the construction of the block layout, i.e. the location of the departments into the workshop, and the second step is the design of the material handling system. The separate optimization of these two aspects of the problem leads to solutions that can be far from the total optimum. In this paper, an integrated approach to the facilities and material handling system design is proposed. Referring to a physical model, named the bay structure , and to a unidirectional AGV system, a genetic approach is proposed to individuate the locations of the departments, the positions of the pickup/delivery stations and the direction of the flow-path. The minimization of material handling cost is adopted as optimality criterion.     

An integrated methodology for automating the determination of layout and materials handling system

There is a severe scanty of models and solution techniques for the determination of layout and the materials handling system when neither are fixed. This is a complex problem for which this paper proposes a new integrated methodology using a knowledge-based/optimisation approach to the problem. The knowledge-base consists of facts and rules to determine the feasibility of using a materials handling equipment type for a given move. The optimisation part determines the layout of machines minimising the materials handling costs and the dead space in the layout using a multi-criteria optimisation model. The methodology aims to minimise materials handling costs, aisle space usage and dead-space in the resulting layout. It is particularly applicable to heavy manufacturing environments. The system outputs the optimum location, configuration and orientation of machines, and the material handling equipment types, their design capacities, utilisations and the assignment of moves to each item of materials handling equipment. The results of a successful application to an example problem are given.     

Client-server model of integrated production facilities

The objective of the reported research is to develop a new design-model of distributed facilities, where production is integrated and operates under computer supported collaboration. The main innovation has been the exploitation of the analogy of the highly effective client-server computing environment for the benefit of production facilities design. As a variant of flexible manufacturing systems, the challenge is to manage the distributed material and information flow. The solution approach developed here is by protocols. The goal is to explain the design of the client-server production model and its coordination protocols, including functions of synchronization and resource allocation. An implementation of the model in an assembly and test facility and its application over the last three years serve to explain the model and illustrate its significance. Time-out and priority assignment protocols are defined and analysed in the context of the model to demonstrate its specific benefits.     

An integrated machine scheduling and personnel allocation problem for large-scale industrial facilities using a rolling horizon framework

Optimization and Engineering - In this study we present an optimization problem where machine scheduling and personnel allocation decisions are solved simultaneously. The machine scheduling...     

Multi-period international facilities location: An algorithm and application

In today's markets, customers want to buy the best quality products at the lowest prices, regardless of where they are produced. Hence, most companies can no longer afford to operate in a single domestic market. To penetrate global markets and obtain their benefits, companies are under tremendous pressure to be competitive and to reduce their production costs. Establishing foreign manufacturing facilities has therefore been taking place rapidly and is further enhanced by trade agreements such as NAFTA. Even though there has been much written on facilities location, in general the literature on international facilities location is rather limited. This paper surveys the available literature and provides an efficient branch and bound procedure for solving the uncapacitated multi-period international facilities location problem. This branch and bound procedure is applied to a case study and tested for its efficiency. The solutions and computation times are compared with those obtained using LINDO. This extensive computational analysis has been extremely promising.     

An applied model for the facilities design problem

A model ia described which can be used to assist in the design of a facility, where the facilities design includes the selection of the materials handling system and the placement of departments within the facility. The model is entitled COFAD, an acronym representing Computerized FAcilities Design. COFAD selects the facilities design which approaches the minimal materials handling system cost. The input requirements and the utilization of COFAD are demonstrated via an example problem. Although it is shown that the model results in good solutions, due to the complexity of the design problem, no claim of optimality can be made.     

An integrated closed-loop supply chain model with location allocation problem and product recycling decisions

Environmental pollutions caused by improper abandoned cartridges increase dramatically nowadays. In Hong Kong, due to abundant quantity of cartridges being used, producers have to optimise their forward and reverse networks to maximise the recycling rate and their profits. In this paper, a comprehensive closed-loop supply chain (CLSC) model is established. This model contains eight partners in CLSC and describes the existing cartridge recycling situation in Hong Kong. In the literatures, many CLSC models were established and studied, but few of them analysed the delivery activity for different kinds of materials extracted from the used products and also, few papers studied the situation that used products are classified into good and poor quality. In this model, delivery activities of different materials are considered and the used cartridges are classified into good-quality ones and poor-quality ones. Producers will have different methods to process them. This problem is formulated into an Integer programming model. Since both delivery routes and delivery quantities problems are known to be NP hard, a novel modified two-stage genetic algorithm (GA) is proposed. A new two-stage encoding algorithm in the proposed GA reinforces the genetic searching ability in tackling this kind of problem. As the model is new in literature, we used Integer Programming to solve the testing instances and benchmark with the proposed algorithm. The results show that a near-optimal solution can be obtained by the proposed GA in a much shorter computational time.     

An integrated framework for multi-scale materials simulation and design

In this paper, we describe initial results of an ongoing research activity involving materials scientists, computer scientists, mathematicians, and physicists from academia, industry and a national laboratory. The present work aims to develop a set of integrated computational tools to predict the relationships among chemistry, microstructure and mechanical properties of multicomponent materials systems. It contains a prototype grid-enabled package for multicomponent materials design with efficient information exchange between structure scales and effective algorithms and parallel computing schemes within individual simulation/modeling stages. As part of our multicomponent materials design framework, this paper reports the materials simulation segment in developing materials design knowledgebase, which involves four major computational steps: (1) Atomic-scale first-principles calculations to predict thermodynamic properties, lattice parameters, and kinetic data of unary, binary and ternary compounds and solutions phases; (2) CALPHAD data optimization approach to compute thermodynamic properties, lattice parameters, and kinetic data of multicomponent systems; (3) Multicomponent phase-field approach to predict the evolution of microstructures in one to three dimensions (1–3D); and (4) Finite element analysis to generate the mechanical response from the simulated microstructure. These four stages are to be integrated with advanced discretization and parallel algorithms and a software architecture for distributed computing systems.     

Satisfying partial demand in facilities location

In this paper we consider the location of new facilities which serve only a certain proportion of the demand. The total weighted distances of the served demand is minimized. We consider the problem in the plane for the location of one facility and on a network for the location of >m-facilities. Some computational experience with these models are reported.     

An integrated model for crossdock operations including staging

Crossdock operations are designed to consolidate and quickly move goods from a variety of origins to a variety of destinations. The key performance characteristics used to measure crossdock performance are outgoing truck cube utilisation and load dwell time in the crossdock. These two measures are at odds with each other, and satisfying one comes at the expense of satisfying the other. The paper develops an integrated crossdock operations model that optimises this trade-off and accounts for incoming and outgoing truck door assignment, staging allocation/location, and load scheduling. The problem is further explored experimentally to determine factor contributions to maximising overall operations revenue. Finally, a genetic algorithm is developed to solve large-scale problems.     

An integrated model for assembly line re-balancing problem

In this paper, an integrated approach for assembly line rebalancing problem (IALRP) is proposed to quickly react and find an optimal rebalancing of the line when disruptive event occurs because of product demand changes. This model is motivated by real-life application of an automotive cable manufacturer which provides more realistic constraints. To solve the problem, we propose a genetic algorithm (GA) hybridised with a heuristic priority rule-based procedure. This hybridisation is used to add more rich seeds to the initial population and consequently to improve the convergence capability and performance of the GA. After the disturbance, we aim to find a rebalance with the proposed approach to maximise the line efficiency and distributing the idle time across the workstations as equally as possible. To evaluate the efficiency of the proposed algorithm, set of samples collected from the literature are used. The real case study and the experiment results show the proposed approach is very effective and competitive.     

Multi-criteria location planning for public facilities in tsunami-prone coastal areas

We present a model for multi-objective decision analysis with respect to the location of public facilities as schools in areas near to coasts, taking risks of inundation by tsunamis into account. A mathematical programming formulation with three objective functions is given. The first objective function is a weighted mean of a minisum and a maximum coverage criterion. The second objective function expresses risk by possible tsunami events; for quantifying this risk, a statistical model for tsunami occurrences by Kaistrenko and Pinegina is applied. The third criterion represents costs. For the solution of the multi-objective optimization problem, we propose a heuristic approach based on the NSGA-II algorithm and compare it with a decomposition technique where the region under consideration is partitioned into smaller sub-regions, and the problem is solved for each separate subregion either exactly or heuristically. Both approaches are tested on two real-life instances from southern Sri Lanka.     

Magnetic materials for integrated cores

Magnetic materials for an integrated magnetic core memory have been developed. The materials are for a storage layer about 1 μm thick and a low reluctance keeper layer. Materials investigated were Co-Ni-Fe for the storage layer and Cr-Ni-Fe for the keeper. Measurements were made ofH_{c}, B_{s}, B_{r}, lambda_{s}, S_{w}, H_{0}, and Hdisturb. Layer stress and adhesion were also measured. Special apparatus, which is described, has been developed to perform some of the measurements. Variation of properties with substrate surface, substrate temperature, and oxygen pressure during evaporation are reported.     

An integrated inventory optimization model for facility location-allocation problem

This paper presents an integrated inventory distribution optimisation model for multiple products in a multi-echelon supply chain environment. Inventory, transportation and location decisions are considered. The objective is to offer practical guideline to the steel retail supply chain practitioners in choosing the correct distribution centre, finding out inventory level at individual inventory keeping points (retailers and distribution centres) point thereby helping them in reducing overall distribution cost. The framework presented endorses systems approach and suggests near-optimal approach to calculating inventory for an individual distributor and his retailers. Two algorithms are used to solve this problem, a novel hybrid Multi-objective Self-learning particle swarm optimiser and Non-dominated sorting genetic algorithm-II. The model and solution methods are tested on real data-sets obtained from organisations in the steel retail environment. The actual data on inventory holding, ordering and transportation costs of distributors and retailers are used as inputs. The decisions like choosing correct set of Distribution centres, keeping optimal regular and safety stock inventory levels are arrived at by applying practical constraints in the supply chain. Model developed assists in effective and efficient distribution of the products manufactured from the optimal location at minimal cost.     

An integrated model for statistical and vision monitoring in manufacturing transitions

Manufacturing transitions have been increasing due to higher pressures for product variety. One dimension of this variety is color. A major quality control challenge is to regulate the color by capturing data on color in real‐time during the operation and to use it to assess the opportunities for good parts. Control charting, when applied to a stable state process, is an effective monitoring tool to continuously check for process shifts or upsets. However, the presence of transition events can impede the normal performance of a traditional control chart. In this paper, we present an integrated model for statistical and vision monitoring using a tracking signal to determine the start of the transition and a confirmation signal to ensure that any process oscillation has concluded. We also developed an automated color analysis and forecasting system (ACAFS) that we can adjust and calibrate to implement this methodology in different production processes. We use a color transition process in plastic extrusion to illustrate a transition event and demonstrate our proposed methodology. Copyright © 2003 John Wiley & Sons, Ltd.     

An integrated model for the production-inventory-distribution problem in the Physical Internet

In contrast to traditional supply chain networks, Physical Internet (PI) is an interconnected open global logistics network based on open PI hubs and standard PI-containers that has the potential to achieve ground-breaking improvements in integrated production-inventory-distribution management. In this paper, to quantify the advantages of PI from a cost performance perspective, we propose a mixed-integer linear programming (MILP) formulation for addressing the problem that combines an integrated production-inventory-distribution decision with PI, which has been addressed separately in the existing literature. The results of computational experiments show that while achieving a comparable or better service level, PI can achieve significant cost savings compared to a traditional supply chain network with a dynamic configuration and a hybrid configuration. Moreover, we investigate the impact of several problem parameter changes on the total costs under each network setting, and managerial insights are derived.     

Analytic design of monitoring facilities for integrated circuit inspection

A method is proposed for the analytic design of monitoring facilities that enables one to choose the characteristics on the basis of user optimality: maximum performance in using the facilities. That method does not require any additional data over and above those that a designer normally disposes of. Translated from Izmeritel’naya Tekhnika, No. 1, pp. 12–14, January, 2009.     

Minimizing work-in-process and material handling in the facilities layout problem

We consider the plant layout problem for a job shop environment. This problem is generally treated as the quadratic assignment problem with the objective of minimizing material handling costs. Here we investigate the relationship between material handling costs and average work-in-process. Under restrictive assumptions, an open queueing network model can be used to show that the problem of minimizing work-in-process reduces to the quadratic assignment problem. In this paper, we generalize these results through a simulation model, and develop a simple secondary measure which allows us to select the layout that minimizes average work-in-process levels from among solutions that are similar with respect to the objective function for the quadratic assignment problem.     

An inclusion model for crack arrest in fiber reinforced materials

A tensile crack bridged by strong and tough fibers is modeled in such a manner that it can be analyzed based on concepts from the mechanics of inclusion. Analytical expressions for the energy release rate, stress intensity factor and crack opening are derived. It is shown that the presence of the supporting fibers reduces the values of those quantities which saturate at a certain level determined by the size and spacing of the fibers.     

Predictive models for setting safe limits in manual materials handling

Most current data on manual handling performance are in the form of single-factor studies using the criterion of maximum weight liftable and measuring its variation with experimental conditions. This does not always help the manager attempting to set safe handling limits as his/her application will involve many of the factors. A recent paper by Drury and Pfeil showed how the task-factors of height of lift and awkwardness of object could be combined with the age and sex of the materials handler to predict performance. This paper is an extension of these methods to incorporate more data on the effects of lifting height, introduce a more general measure of awkwardness and modify the model to cover extended periods of lifting rather than a single maximum exertion.

It is shown that the criterion of duration of lifting at constant weight leads to the same results as the criterion of maximum weight lifted. Other findings are that the height of the object at both the beginning and the end of the lift are required to specify performance, and that carrying performance can be treated as an extension of static lifting performance.