Concurrent engineering of work and production systems

Concurrent Engineering (CE) is one of the most important concepts for reducing development time and improving the quality of products and their related processes. However, there is a significant lack of methods to support the planning of production systems and personnel in a CE environment. This article presents an approach to the development of such methods and their preliminary concepts. It focuses on the selection of inspection tools, personnel, and the design of shop floor control systems.     

Supply quality management with wholesale price and revenue-sharing contracts under horizontal competition

In a number of industries (e.g., the airplane industry, aerospace industry, auto industry, or computer industry), certain suppliers essentially have a monopoly on the production technology for key components, and inevitably manufacturers in these industries have common suppliers. A key part of manufacturers’ work with suppliers concerns improving the quality of their respective products, which gives rise to a collaborative activity usually termed as “supply quality management”. When the manufacturers are competitors, they do not wish to see a common supplier dividing his involvement in quality improvement unequally between themselves and their rivals. However, as the suppliers collaborate with several manufacturers, it is highly questionable whether their efforts will be strictly equivalent for each manufacturer. In this paper, a non-cooperative dynamic game is formulated in which a single supplier collaborates with two manufacturers on design quality improvements for their respective products. The manufacturers compete for market demand both on price and design quality. The paper analyzes how each party should allocate resources for quality improvement over time. In order to take into account the potential coordinating power of the compensation scheme adopted in this type of decentralized setting, we compare the possible outcomes under a wholesale price contract and a revenue-sharing contract.     

基于PLSR的多级制造过程关键质量特性识别方法

为解决多级制造过程关键质量特性识别中多质量特性之间的相关性问题,将偏最小二乘回归方法(Partial Least Squares Regression, PLSR)引入模型构建与分析中。首先应用状态空间方法建立多级制造过程关键质量特性识别模型,进而利用PLSR方法解决质量特性间的多重共线性问题并进行模型分析,识别关键质量特性,最后以卷烟生产过程为例介绍了该方法的应用。实例表明,该方法不仅可以有效识别多级制造过程关键质量特性,而且能够建立各级过程的输出质量对最终产品质量的影响及其质量特性之间相互关系的模型,反映多级生产过程的结构特征和各级过程质量特性之间的因果关系,为多级制造过程质量分析与控制提供依据。     

Economic manufacturing quantity,optimum process mean,and economic specification limits setting under the rectifying inspection plan

Economic manufacturing quantity, process mean, and specification limits setting are three important methods for the inventory and quality control problems. In the imperfect production system, we usually consider the manufacturing quantity for reducing the inventory cost, determine the process level for reducing the production cost, and select the specification limits for screening the products. In this paper, we propose the above integrated model based on the application of rectifying inspection plan for obtaining maximum expected total profit of product. The asymmetric quadratic quality loss function is adopted for measuring the product quality. The sensitivity analyses of parameters are provided for illustration.     

我国工业投资、产能过剩与通胀通缩转换分析

利用向量自回归模型和脉冲响应函数以及结构性通胀模型考察了投资"潮涌"现象对通胀水平的冲击,深入阐述了产能过剩与通货膨胀并存的具体原因以及长期产能过剩条件下通胀与通缩转换的可能性.指出投资"潮涌"拉动了基础原材料行业的需求,引发物价水平上升.同时,工农业部门生产率差距也倒逼着农产品价格不断上涨,推高通胀水平.地方政府和国企的投资冲动、制造业在CPI中比重较低以及通胀成因复杂是我国产能过剩与通胀并存的真正原因,从长期来看,产能过剩行业的生存空间日益缩小,投资拉动需求推高价格上涨的传导机制不可持续,通胀向通缩转换具有很大可能性.最后,给出了相应的政策建议.     

The use of artificial intelligence technique for the optimisation of process parameters used in the continuous casting of steel

The productivity and quality of a continuous caster depend mainly on process parameters, i.e. casting speed, casting temperature, steel composition and cleanliness of the melt, water flow rates in the different cooling zones, etc. This work presents the development of an algorithm, which incorporates heuristic search techniques for direct application in metallurgical industries, particularly those using continuous casting process for the production of steel billets and slabs. This is done to determine the casting objectives of maximum casting rate as a function of casting constraints. These constraints are evaluated with the aid of a heat transfer and solidification model based on the finite difference technique, which has been developed and integrated with a genetic algorithm. The essential parts of continuous casting equipment, which must be subjected to monitoring, as well as a methodology of mathematical model and physical settlements in each cooling region, are presented. The efficiency of the intelligent system is assured by the optimisation of the continuous casting operation by maximum casting rate and defect-free products. This approach is applied to the real dimension of a steel continuous caster, in real conditions of operation, demonstrating that good results can be attained by using heuristic search, such as: smaller temperature gradients between sprays zones, reduction in water consumption and an increase in casting speed.     

Multivariate analysis for the assessment of factors affecting industrial competitiveness: The case of Greek food and beverage industries

Principal component analysis is integrated with canonical analysis to examine aspects of the competitiveness of two different sectors of the Greek manufacturing, i.e. the food and the beverage industries. Different measures of labour productivity, vertical integration, technological innovation and size of the firms which are considered as critical factors of industrial competitiveness are used in the application of the principal component analysis. Canonical analysis is then applied to correlate the variables of labour productivity with the other variables. In the case of the food and beverage integrated sector, the results of the principal component analysis pinpoint that there are two main principal components: (a) labour productivity and vertical integration, and (b) technological innovation and size. The first factor depicts the internal organizational, structural and production processes changes realized so that the competitiveness of the sector firms improves, whereas the second factor reflects the response of the sector to technological and growth trends. The two variables of labour productivity are affected by the degree of vertical integration and, at a lesser degree, by a common factor of the size of the firm and the level of investment for technological innovation. Copyright © 2000 John Wiley & Sons, Ltd.     

Synchronized production–distribution planning in a single-plant multi-destination network

This paper examines the flow synchronization problem between a manufacturing location and multiple destinations. Multiple products can be shipped from the manufacturing location to different locations via multiple transportation modes. These transportation modes may have different transportation lead times. The transportation costs structure of the different transportation modes offer economies of scale and can be represented by general piecewise linear functions. The production system at the manufacturing location is a serial process with a bottleneck stage. At the bottleneck stage, a predetermined production sequence must be maintained as is the case in some process-based industries. We propose a tight mixed integer programming model for integrated planning of production and distribution in the network. We show that by adding simple valid inequalities and special 0-1 variables, major computational improvements can be achieved when solving this problem with commercial solvers such as Cplex. We also propose a sequential solution approach, based on the independent, but synchronized, solutions of the production and distribution sub-problems. Finally, the solution methods proposed are tested experimentally for realistic problems and the advantage of integrated planning over independent but synchronized planning is assessed.     

A multi-phase mathematical programming approach for effective supply chain design

A supply chain is an alliance of independent business processes, such as supplier, manufacturing, and distribution processes that perform the critical functions in the order fulfillment process. Effective design and management of supply chains assists in production and delivery of a variety of products at low cost, high quality, and short lead times. Although the importance of supply chain design is emphasized in the literature, few formal decision models have been proposed for this purpose. This paper presents a multi-phase mathematical programming approach for effective supply chain design. More specifically, the methodology develops and applies a combination of multi-criteria efficiency models, based on game theory concepts, and linear and integer programming methods. Model application and insights are detailed through numerical illustrations.     

Scheduling of Products with Common and Product-Dependent Components Manufactured at a Single Facility

This paper analyses a scheduling problem concerned with the production of components at a single manufacturing facility where the manufactured components are subsequently assembled into a finite number of end products. Each product is composed of a common component and a product-dependent component, and completion time of a product is determined by the completion time of the last of two components. All the components are manufactured in a batch process at the single facility and, during the batch process, the manufactured components are individually moved to the next (assembly) station; switching from production of product-dependent components to common components only incurs a set-up cost. The solution properties are characterized subject to the mean flow time measure, based upon which an efficient branch-and-bound solution algorithm is exploited.     

Increasing flexibility and productivity in Industry 4.0 production networks with autonomous mobile robots and smart intralogistics

Manufacturing flexibility improves a firm’s ability to react in timely manner to customer demands and to increase production system productivity without incurring excessive costs and expending an excessive amount of resources. The emerging technologies in the Industry 4.0 era, such as cloud operations or industrial Artificial Intelligence, allow for new flexible production systems. We develop and test an analytical model for a throughput analysis and use it to reveal the conditions under which the autonomous mobile robots (AMR)-based flexible production networks are more advantageous as compared to the traditional production lines. Using a circular loop among workstations and inter-operational buffers, our model allows congestion to be avoided by utilizing multiple crosses and analyzing both the flow and the load/unload phases. The sensitivity analysis shows that the cost of the AMRs and the number of shifts are the key factors in improving flexibility and productivity. The outcomes of this research promote a deeper understanding of the role of AMRs in Industry 4.0-based production networks and can be utilized by production planners to determine optimal configurations and the associated performance impact of the AMR-based production networks in as compared to the traditionally balanced lines. This study supports the decision-makers in how the AMR in production systems in process industry can improve manufacturing performance in terms of productivity, flexibility, and costs. 

     

Cell formation using fuzzy relational clustering algorithm

Cellular manufacturing is a useful way to improve overall manufacturing performance. Group technology is used to increase the productivity for manufacturing high quality products and improving the flexibility of manufacturing systems. Cell formation is an important step in group technology. It is used in designing good cellular manufacturing systems. The key step in designing any cellular manufacturing system is the identification of part families and machine groups for the creation of cells that uses the similarities between parts in relation to the machines in their manufacture. There are two basic procedures for cell formation in group technology. One is part-family formation and the other is machine–cell formation. In this paper, we apply a fuzzy relational data clustering algorithm to form part families and machine groups. A real data study shows that the proposed approach performs well based on the grouping efficiency proposed by Chandrasekharan and Rajagopalan.     

Impact of computerization on firm performance: a case of Shanghai manufacturing enterprises

The impact of computer-related input on firm productivity is not well understood in the developing world, including China. The present study contributes to this area by analyzing data collected from a sample of Shanghai manufacturing enterprises. Adopting a Cobb–Douglas production function, we find a positive relationship between computer personnel and enterprise output. The efficiency of enterprises, however, was shown to be generally low according to data envelopment analysis. The level of computerization was shown to make a positive contribution to improving efficiency in non-state-owned enterprises in both heavy and light industries. This was also shown to be the case for state-owned enterprises in heavy industry.     

Models for concurrent product and process design

We propose procedures to address product design and manufacturing process configurations concurrently in environments characterized by large degrees of product proliferation. Exploiting the intrinsic flexibility of product and process design, we present two approaches that synchronize production flows through the manufacturing system. These approaches integrate product and manufacturing system design decisions with operational concerns and provide powerful means for managing production in environments characterized by a proliferation of products. Experimental results show that the proposed methods can substantially reduce manufacturing lead times, work in process (WIP), and overall system complexity.     

A closed-loop logistics model for remanufacturing

Recoverable product environments are becoming an increasingly important segment of the overall push in industry towards environmentally conscious manufacturing. Integral to the recoverable product environment is the recoverable manufacturing system that focuses on recovering the product and extending its life through remanufacture or repair. Remanufacturing provides the customer with an opportunity to acquire a product that meets the original product standards at a lower price than a new product. The flow of materials and products in this environment occurs both from the customer to the remanufacturer (reverse flow), and from the remanufacturer to the customer (forward flow). Since most of the products and materials may be conserved, essentially this forms a closed-loop logistics system. We present a 0–1 mixed integer programming model that simultaneously solves for the location of remanufacturing/distribution facilities, the transshipment, production, and stocking of the optimal quantities of remanufactured products and cores. We also discuss the managerial uses of the model for logistics decision-making.     

低碳约束下湖南省产业结构优化研究

在湖南省"十二五"规划工业产业节能减排的背景下,如何在碳减排目标的基础上,实现产业结构优化,成为湖南省面临的重大挑战.本文构建低碳约束下湖南省主导产业选择指标体系,计算并选取湖南省无低碳约束和有低碳约束下的主导产业.进一步,本文设计无低碳约束、弱低碳约束和强低碳约束三种情景模拟,分析不同的低碳约束条件对湖南省主导产业选择的影响.本文结论如下:1)无低碳约束条件下,湖南省主导产业包括有色金属冶炼及压延加工业等碳生产力较低的行业,低碳约束条件下,湖南省主导产业包括食品制造业等碳生产力较高的行业.这表明,考虑低碳约束条件,湖南省主导产业由碳生产力较低的行业向碳生产力较高的行业转变.2)情景模拟结果表明,一些传统支柱型产业仍是湖南省产业结构优化中需重点发展的产业,且随着低碳政策的深化和节能减排目标的扩大,战略性产业如医药制造业成为主导产业,在产业结构优化中发挥中坚作用.     

Enhanced multi-Hoffmann heuristic for efficiently solving real-world assembly line balancing problems in automotive industry

In production systems of automobile manufacturers, multi-variant products are assembled on paced final assembly lines. The assignment of operations to workplaces and workers deter mines the productivity of the manufacturing process. In research, various exact and heuristic solution procedures have been developed for different versions of the so-called assembly line balancing problem.     

An incomplete markets model of business cycles

This paper explores the effects of incomplete markets and positive spillovers on aggregate and industry output behavior. We consider an economy composed of a fixed set of infinitely-lived industries. When industries coordinate production decisions they jointly improve their productivity. Markets are missing, however, in the sense that industries cannot automatically form the most productive coalitions due to the presence of communication frictions. The degree of coordination between industries is determined by a random matching process from which complex coalitions of industries emerge through bilateral industry interactions. High production by an industry improves the probability with which it communicates with other industries, creating a positive spillover effect on the productivity of the rest of the economy. Aggregate output behavior exhibits both persistent fluctuations as well as procyclical productivity.     

面向单小批量产品设计的质量屋模型改进研究

为了使单小批量产品设计能够充分满足顾客需求,提高顾客满意度和忠诚度,帮助企业获得市场竞争优势。本文结合单小批量产品生产自身的特点,在系统的研究和总结传统的质量屋理论与方法及最新进展的基础上,对质量屋模型进行改进,利用设计规则间的影响系数和客户需求与设计规则之间的关系矩阵求出价值矩阵后,借助0—1整数规划技术求解改进的质量屋模型,从而使单小批量产品的设计规则可以按照顾客需求重新排列优先次序,最后通过S公司某单小批量产品的设计过程对模型进行验证。本文的研究意义在于使单小批量产品设计能够完全满足顾客的个性化需求,从而保证了企业最终生产出符合顾客和市场需求的单小批量产品。     

Software modelling of manufacturing systems: A case for an object-oriented programming approach

With the recognition of the importance of Computer Integrated Systems (CIM) in improving manufacturing productivity, there is a pressing need for good software modelling approaches to support efficient design and control of manufacturing systems. Software design concepts based on Object-Oriented Programming (OOP) are emerging as powerful techniques for developing large scale software systems. This paper presents important features of object-oriented computing and the relevance of such an approach in modelling and developing software for manufacturing systems.