多单元制造系统布局设计

从布局设计的角度,提出多单元制造系统的概念,把各种制造系统的布局问题转化为多单元制造系统布局设计问题,包括设备布局和制造单元布局两个方面。对于设备布局问题,给出一种优化建模与虚拟现实技术相结合的求解策略;对于单元布局问题,给出一种集成的布局设计方法。     

带检测环节的制造单元布局优化

针对带检测环节的智能制造单元，考虑其具有随机性因素的特点，本文对其机器布局问题进行研究。首先对该智能制造单元的生产过程及特点进行分析，建立其机器布局优化问题的随机非线性整数规划的数学模型；然后建立该智能制造单元对应的仿真模型，对该优化问题进行求解；最后分析抽检率的变化对最优解造成的影响，并对该智能制造单元的性能指标进行方差分析，研究不同的布局方案和抽检率对系统性能的影响程度。研究成果为企业进行智能制造单元的机器布局提供决策依据。     

U型生产单元可重构设施布局方法研究

针对制造企业生产单元重新布局的决策问题,以U型生产单元为研究对象,以物料搬运成本、单元重构成本和生产时间损失成本之和最低为优化目标,考虑了重新布局的预算约束以及各类惩罚约束,建立了单元生产可重构设施布局决策的集成模型。设计了决策问题的遗传算法,以实验测试方式确定遗传算法的参数设置,避免陷入局部最优,并通过实例求解,验证了模型和算法的可行性。根据U型单元现有布局、下一周期订单数量和产品工艺要求等信息,利用上述模型和算法进行分析和优化,为企业进行新一轮的生产组织提供决策支持。     

制造单元构建评价体系的研究

单元化制造系统的构造设计可分为两个阶段 ,单元构建和单元布局设计 .在单元化制造系统构建的过程中 ,单元构建的评价起了关键性指导作用 .本文首先综述了已有的单元构建评价指标 ,并对评价体系提出了需求 ,随后建立了单元构建的评价体系 ,它由三个部分组成 :静态评价、动态评价以及综合评价 .最后文章展望了单元评价体系今后的研究发展方向 .     

南光CIMS应用工程实施概述

本文主要介绍南光CIMS应用工程实施概况,对其工程的总体结构及部分分系统结构进行了详细说明,在制造层的布局上提出了在CIMS环境下,应用精节生产思想,结合企业的产品特点和生产规律建立符合中国国情的单元制造系统。     

基于CRAFT的多阶段柔性设备布局优化算法

多阶段设备布局下的总成本包括设备拆装成本、物料搬运成本以及区域利用成本,问题的目标是最小化总成本.首先,在分析问题的基础上,建立基于多阶段设备布局优化目标的数学模型;其次,采用改进的CRAFT启发式算法优化单阶段设备布局;进一步,提出基于单阶段设备布局算法的多阶段启发式算法,优化多阶段设备布局;最后,数值实验表明算法优化后总成本降幅达28.57%.     

基于Plant Simulation的智能制造测试床仿真模型 设计与应用

为了验证智能制造测试床的整体布局设计和制造工艺在生产运营环境下的合理性，利用西门子Plant Simulation工厂仿真软件进行生产节拍和设备利用率分析。首先，建立了按订单生产运行的制造生产线二维仿真模型，根据生产要求对二维仿真模型进行输入参数设定，并根据二维仿真模型运行后得到的分析统计结果进行工艺布局、物流布局和制造策略的优化。然后，在二维仿真模型基础上，为了让仿真模型在建设阶段和运营阶段具有更直观的展示效果，基于原三维设计图，在三维仿真模型中替换或导入各对象的三维模型，并运用Simltalk语言编写精细的三维位置坐标和动作路径动画程序，对仿真模型进行三维效果优化。结果表明优化后的智能制造测试床三维仿真模型可以实现与实际生产一致的业务运行模式，它具有更形象、逼真的动态运行展示效果。仿真结果可指导智能制造测试床的建设与优化，且在测试床投入运营后，仿真模型还能够接受运营数据以对测试床进行持续迭代的优化。提出的仿真模型设计方法为实现智能制造测试床的“数字孪生”奠定了基础。     

企业设备布局方式的仿真

针对设备布局问题研究的不足,分析了3种常用设备布局方式(传统直线形布局、U形布局和单元式布局)的特性,利用仿真工具对一电子制造企业做了个案研究.仿真结果表明当产品品种单一或需求量较少时,U形布局的单产品生产周期相对其他两种布局方式要短一些;当品种较多或需求量较大时,单元式布局能获得最佳效益.     

非大量生产类型的精益生产

针对非大量生产类型的精益生产进行了系统探讨.追溯精益生产方式的起源——丰田生产方式,提出了流水线在精益生产中的地位.以虚拟成组生产单元为依托,通过投批组的建立,来解决非大量生产类型的零件品种多、批量不大的问题.投批组确保了虚拟成组生产单元的稳定性,为拉式生产提供了可能.通过JIT的生产均衡,把拉式生产时间均衡化,并且通过降低虚拟成组生产单元的生产节拍来追求精益生产的尽善尽美.     

基于SA-QPSO算法的多层制造单元内部布局方法

针对多层制造单元内部的设备布局优化问题,本文建立考虑单元尺寸、物料搬运量、损失时间以及单元稳定性的多目标优化数学模型。为更快速、高效地求解该问题,使用模拟退火算法（Simulated Annealing,SA）确定单元内设备所在平面以及层面,使用量子粒子群算法（Quantum Particle Swarm Optimization,QPSO）确定设备具体坐标值和所在高度。以某汽车零件加工车间为实例,运用SA-QPSO算法生成直线形、“U”形和环形3种最优空间布局方案,验证了SA-QPSO算法在多层制造单元内部布局方法设计方面的可行性。     

A similarity score-based two-phase heuristic approach to solve the dynamic cellular facility layout for manufacturing systems

The dynamic cellular facility layout problem (DCFLP) is a well-known NP-hard problem. It has been estimated that the efficient design of DCFLP reduces the manufacturing cost of products by maintaining the minimum material flow among all machines in all cells, as the material flow contributes around 10–30% of the total product cost. However, being NP hard, solving the DCFLP optimally is very difficult in reasonable time. Therefore, this article proposes a novel similarity score-based two-phase heuristic approach to solve the DCFLP optimally considering multiple products in multiple times to be manufactured in the manufacturing layout. In the first phase of the proposed heuristic, a machine–cell cluster is created based on similarity scores between machines. This is provided as an input to the second phase to minimize inter/intracell material handling costs and rearrangement costs over the entire planning period. The solution methodology of the proposed approach is demonstrated. To show the efficiency of the two-phase heuristic approach, 21 instances are generated and solved using the optimization software package LINGO. The results show that the proposed approach can optimally solve the DCFLP in reasonable time.     

Unit load and material-handling considerations in facility layout design

The effectiveness of a layout design cannot be completely measured if the operational characteristics of the manufacturing system are ignored. There is, therefore, a need to develop integrated manufacturing system design models. In this paper, the integration of unit load and material-handling considerations in a facility layout design is presented. This integration is based on a stochastic model that captures the operational characteristics of the manufacturing system and a nonlinear mixed-integer program that incorporates a department formation and facility layout. The non-linear mixed-integer program is solved using a simulated annealing-based algorithm. Analytical results for different manufacturing system scenarios are presented and compared with results obtained using alternative QAP-type formulations. Based on our experiments and the characteristics of the different formulations, key observations are presented and discussed.     

Integrating occupational health and safety in facility layout planning,part I: methodology

An influential factor affecting the efficiency of a manufacturing facility is its layout. In a production facility, measure for efficiency can be based on the total cost of transporting the items between different departments and throughout the facility. However, other factors may influence efficiency of the manufacturing facility too. As such are: supporting the organisation's vision through improved material handling, material flow and control; effectively assigning people, equipment, space and energy; minimising capital investment; adaptability and ease of maintenance; as well as providing for employee safety and job satisfaction. By incorporating health and safety measures in the initial design of a facility layout, the organisation may avoid money and manpower loss resulting from industrial accidents. This paper proposes a facility layout planning methodology which integrates the occupational health and safety (OHS) features in the early design of a facility layout. The model considers transportation cost in the facility as well as safety concerns. By this means, the OHS issues are reflected prior to the construction of a facility.     

Cellular machine layout based on the Segmented Flow Topology

This paper introduces a facility layout design procedure for converting an existing manufacturing system with a predefined aisle structure to a cellular manufacturing system based on the 'segmented flow topology' (SFT) developed by Sinriech and Tanchoco. The proposed procedure is aimed at finding the best machine grouping, along with the locations of pick-up and delivery stations and machine layout for each cell based on an existing facility. The objective is to minimize the total material handling cost. In contrast to previous work in this area, the proposed design procedure takes into account both distance and material flow in forming machine clusters. In addition, a revised cost model for material handling system, which accounts for different aspects of capital and operating cost, is presented.     

离散生产系统车间设施布置优化

分析了离散生产系统车间平面布置的目标函数,生产单元之间的距离计算方法,提出了在非等面积生产单元布置条件下,缩减解空间的两阶段优化布置法。借助计算机的高速运算能力,采用智能最优化算法,对缩减的解空间进行优化搜索,确定出各生产单元的最优位置,在此基础上,根据各生产单元面积比例对车间面积分别按行和列进行分配,确定出初步布置方案,最后对各单元的面积形状进行规整化处理后,得到车间优化布置方案。     

Solution of facility layout problems with pickup/drop-off locations using random search techniques

Due to non-polynomial hardness, the facility layout problem (FLP) becomes more critical when pickup/drop-off (P/D) locations are considered in the design of an open field layout under a manufacturing environment. This paper proposes an indigenous model of the facility layout problem based on random search techniques and its solution methodology using a genetic algorithm (GA), simulated annealing (SA) and a hybrid algorithm (HA). The paper illustrates the performance of different random search operating parameters in solving the facility layout problem considering P/D locations along the periphery of rectangular machine blocks. The preliminary experiments were carried out on three facility layout test problems having six, eight and ten machines in order to fix the different operating parameters such as crossover operator, crossover rate, initial temperature, temperature reduction factor, number of generations, population size, etc. The results of extensive preliminary experimentation were utilized to solve facility layout problems having 12 and 18 machines and, finally, were compared with the existing procedures in the literature. The experimental tables and related analysis performed via the solution methods by applying GA, SA and HA revealed that random-search-based modeling of FLP considering P/D and its solution as suggested in this paper is worth pursuing.     

A simulated annealing algorithm based on a closed loop layout for facility layout design in flexible manufacturing systems

Facility layout design problems in flexible manufacturing systems (FMS) differ from traditional facility design problems and are more difficult to solve because there are more constraints that must be considered (i.e., cell shape, cell orientation, pick-up and drop-off point positions). The focus of this paper is on the closed loop type layout, which is based on a predetermined layout pattern. This layout pattern is commonly found in manufacturing settings since it requires a simplified material handling system configuration and since it facilitates a modular and expandable layout structure. The open-field type layout problem, where there is no predetermined layout pattern, may potentially have a more efficient configuration, since there are fewer restrictions. However, this problem is more difficult to solve and may result in configurations that are not desirable due to the lack of structure or modularity. The procedure developed in this paper improves the efficiency of the closed loop configuration by changing the rectangular shape of the loop to different sizes. In many cases, the resulting closed loop layout proves to be as efficient as the open field layout. A simulated annealing procedure (SA-CL) is used to search for the configuration that minimizes the total material handling costs. A comparison of the results with existing methods indicates that, based on solution quality and computational time, the SA-CL offers a favourable alternative for efficient layout design.     

Facility layout optimization using simulation and genetic algorithms

Traditionally, the objective of a facility layout problem has been to minimize the material handling cost of the manufacturing system. While it is important to reduce the amount of material handling, the traditional methods do not address the actual time at which the material is transported. In today's short cycle time production environments, the timing of material movement may have a bigger impact on the productivity of the system than its cost. In this paper, a facility layout optimization technique is presented that takes into consideration the dynamic characteristics and operational constraints of the system as a whole, and is able to solve the facility layout design problem based on a system's performance measures, such as the cycle time and productivity. Each layout solution is presented in the form of a string that is suitable for analysis by a genetic algorithm technique. These solutions are then translated into simulation models by a specially designed automated simulation model generator. Genetic algorithms are used to optimize the layout for manufacturing effectiveness while simulation serves as a system performance evaluation tool. Combined with a statistical comparison technique to reduce the simulation burden, the test results demonstrate that the proposed approach overcomes the limitations of traditional layout optimization methods and is capable of finding optimal or near optimal solutions.     

Integration of occupational health and safety in the facility layout planning,part II: design of the kitchen of a hospital

Facility layout design has an important effect on the performance of manufacturing systems. It intends to determine relative location of departments and machines within a plant. A good layout design must ensure that a set of criteria and objectives are met and optimised, e.g. area requirements, cost, communication and safety. The most common objective used in facility planning methods is to minimise the transportation cost. However, factors such as the plant safety, flexibility for future design changes, noise and aesthetics must be considered as well. In this paper, a case study is carried out to investigate the safety concerns in facility layout design. In this regard, a facility layout planning methodology, integrating occupational health and safety (OHS) is presented. This methodology considers transportation cost as well as safety in the facility design. By this means, OHS issues are considered at the design stage of the facility. In other words, this research demonstrates the improvements in the layout design by integrating safety aspects.     

Capability-based distributed layout approach for virtual manufacturing cells

It is shown in the literature that in highly volatile manufacturing environments functional job shops and classical cellular manufacturing systems do not perform well. Classical cellular manufacturing systems are very sensitive to changing production requirements due to their limited flexibility. In order to adapt cellular manufacturing systems to volatile manufacturing environments, the virtual cellular manufacturing concept was proposed in the 1980s by the National Bureau of Standards in USA. This concept is similar to group technology where job families are processed in manufacturing cells. The main difference between a virtual cell and the classic cell is in the dynamic nature of the virtual manufacturing cell; whereas the physical location and identity of classic cell is fixed, the virtual cell is not fixed and will vary with changing production requirements. The virtual manufacturing cell concept allows the flexible reconfiguration of shop floors in response to changing requirements. In the literature, the formation and scheduling process of virtual cells are clearly explained and researched in detail. However, the layout issue is not addressed entirely. Virtual cells are generally formed over functionally divided job shops. Forming virtual cells over a functional layout may adversely affect the performance of a virtual cellular manufacturing system. There is a need to search for different layout strategies in order to enhance the performance. The distributed layout approach may be a better alternative for virtual cellular manufacturing applications. In this research paper, a novel capability-based approach is proposed for the design of distributed layouts. A simulated annealing based heuristic algorithm is developed from the distributed layout. The proposed approach is tested with a problem with real data. An example is also shown in order to give an idea about the superiority of a capability-based distributed layout over the functional layouts in forming virtual manufacturing cells.