A systems analysis approach to solving office work system health and performance problems

This paper describes a systems analysis approach to human performance in office work systems. The approach, integrating both micro- and macroergonomic aspects, provides a process for more comprehensive, systematic solutions. This systems approach is designed to assess office workers' performance and effectiveness problems within technology intensive office work environments and provide realistic solutions for improving performance. The approach incorporates micro- and macroergonomic factors to adequately address the performance and stress and health-related problems associated with modern office work systems. The seven step approach consists of: defining the problems; setting the objectives and developing alternatives; modelling alternatives; evaluating alternatives; selecting an alternative; planning for implementation; and evaluation, feedback and modification. A detailed schematic presentation of these steps is provided. Solutions or alternatives are proposed to minimize the identified problem factors and to improve performance and the quality of work life.     

Minimum Cost 100% Inspection Systems with Inspection Error

A field failure in certain products has the potential to cause human suffering and/or loss of life. To the manufacturer, these failures will result in a significant external failure cost. In this paper, cost minimization models are developed to determine an optimal inspection system for multiple 100% attribute inspections with inspection error. An example involving the visual inspection of a braze joint in a cardiac biopsy device is presented to illustrate the use of the models. A key result is that a system requiring an item to pass every inspection in order to be shipped to a customer is not always the best alternative. Examples illustrating the sensitivity of the model results to key cost and operational parameters are shown.     

A hybrid approach to machine-tool selection through AHP and simulation

The selection process of a machine tool has been a critical issue for companies for years, because the improper selection of a machine tool might cause many problems having a negative effect on productivity, precision, flexibility, and a company's responsive manufacturing capabilities. Therefore, in this paper, to determine the best machine tool satisfying the needs and expectations of a manufacturing organization among a set of possible alternatives in the market, a hybrid approach is proposed, which integrates an analytic hierarchy process (AHP) with simulation techniques. The AHP as one of the most commonly used multiple criteria decision-making methods is used to narrow down all possible machine tool alternatives in the market by eliminating those whose scores (or weights) are smaller than a determined value obtained under certain circumstances. Then, a simulation generator is used first to automatically model a manufacturing organization, where the ultimate machine tool will be used, and second to try each alternative remaining from the AHP as a scenario on the generated model. Finally, the final alternative is selected by using the unit investment cost ratio, which is calculated by dividing the investment cost per year of each alternative by the additional number of produced units obtained from the simulation experiment of the relevant alternative.     

A robust design to reduce variability in glass container inspection

This article presents research efforts made to assist a Fortune 500 glassmaker in reducing the variability of its automated visual inspection systems in assessing product quality. Through interviewing line workers, engineers and managers, and direct observations of the inspection process possible causes leading to large variability observed in the inspection process were identified. Responding to these findings, solutions related to equipment setup, job changes, and operational procedures were suggested in order to minimize the inspection process variations as well as to improve the replicability of the inspection stations. Additionally, a unique statistical experiment was conducted to analyze how three factors (namely, operator, defect size, and threshold value used) would affect the mean of the defective ratio. A robust design aiming at controlling these variations was then given to optimize the system's performance.     

视觉检测技术及应用

视觉检测技术,尤其是基于三角法的主动和被动视觉检测技术具有非接触、速度快、柔性好等特点,是一种先进的检测手段,适合现代制造业的需要。文章论述了视觉检测技术原理,讨论了已经研制的多个实际视觉检测系统,从不同角度展示了视觉检测技术在现代制造业中广阔的应用前景。     

数字化检测在MES中的应用研究

讨论了机械制造企业中三维数字化检测的相关技术,进行了基于DMIS标准的数字化测量研究.通过三维检测技术与生产车间制造执行系统(MES)的结合,完成了基于三维轻量化模型的检验工艺管理、检验任务的执行与管理、产品质量数据和状态的可视化管理,以及产品的质量审理和追溯.这些研究实现了机械制造企业检验的自动化和无纸化,达到了对检...     

电力隧道自动巡检机器人设计与运动仿真

针对现有电力隧道巡检机器人自动化程度不足、视野和观测角度有限的问题,设计了一款子母式自动巡检机器人。其中：具有移动功能的巡检机器人母机能够完成主要的日常巡检工作,并具备越障、避障能力;具有攀爬功能的子机能够完成复杂环境、极限角度条件下的勘测任务。子、母机共同协作可完成整个电力隧道的自动化巡检。首先,基于总体功能需求,提出了巡检机器人各模块的具体形式,并完成了其自动巡检的逻辑系统分层设计。然后,基于虚拟样机技术,在ADAMS (automatic dynamic analysis of mechanical systems,机械系统动力学自动分析)软件中建立电力隧道运行环境,并结合运动学仿真分析结果优化巡检机器人母机的结构,以提升机器人在隧道内作业的平稳性并确保其所搭载的传感器均能正常工作。结果表明,母机结构优化后,巡检机器人能够平稳运行,传感器平台的抖动幅度在5 mm内,且搭载的各传感器均能正常工作,验证了该机器人方案设计的合理性。相关理论研究结果可为电力隧道自动巡检机器人物理样机的研制提供可靠的技术支撑。     

Workflow analysis of production lines with complete inspection and rework loops

We study the flows induced by different rework loops in serial manufacturing systems with inspection stations. Average values of these flows and queuing network formulas are used for performance evaluation and optimisation of production lines. An application is presented for solving jointly the problems of inventory control and inspection station allocation in a CONWIP production line.     

Routing-based reactive scheduling policies for machine failures in dynamic job shops

A scheduling and control system can be viewed as a vital component of modern manufacturing systems that determines companies' overall performance in their respective supply chains. This paper studies reactive scheduling policies developed against unexpected machine failures. These reactive policies are based on rerouting the jobs to their alternative machines when their primary machine fails. Depending on the subset of the jobs considered for rerouting, the long-term performance of four policies are tested under various conditions. Expecting that these rerouting policies would bring an extra load for a material-handling system (MHS), a dynamic job shop environment was studied with and without a MHS. It is shown that the proper selection of a good reactive policy is based not only on the system characteristics such as utilization, machine down times and frequency of machine failures, but also on the MHS capacity (in terms of speed and number of MH devices). The extensive experiments show that when the MHS is not a bottleneck and/or the down times are long enough to compensate the cost of extra rerouting, rerouting all affected jobs to their alternative machines proves to be the best policy. However, when the MHS cannot handle the extra load due to rerouting or the down times are relatively short, then rerouting only the jobs that will arrive to the failed machine during repair performs the best.     

Assessing binary measurement systems and inspection protocols utilizing follow-up data

Industry uses inspection protocols to protect customers from receiving non-conforming product. The two error rates of these systems are the chance of shipping non-conforming product (customer's risk) and the chance of rejecting good product (producer's risk). We investigate the properties of two inspection protocols. In these protocols, the customer uses a gold standard measurement system that determines if received components are conforming. We show that with the first inspection protocol, we can estimate its error rates using only production data. With the second protocol, we propose adding a small measurement assessment study to allow estimation of the error rates.     

Haptic modeling for a virtual coordinate measuring machine

Introducing a haptic device into coordinate measuring machine (CMM) inspection path planning leads to the proposal of a novel CMM off-line inspection path planning environment, a haptic virtual coordinate measuring machine (HVCMM), which makes use of the haptic modeling technique for CMM off-line programming. The HVCMM is an accurate model of a real CMM, which simulates a CMM's operation and its measurement process in a virtual environment with haptic perception. In this paper, a simple and effective mechanics model is implemented for the proposed HVCMM. The HVCMM enables CMM off-line programming to take place exactly as if an operator were in front of a real CMM and moving a real CMM probe. Even more, operators can feel the collision between the CMM and a part. Since there is a force feedback when the probe reaches the surface of the part, besides showing the contact in the HVCMM environment, it is much easier to generate a collision-free probe path than using other off-line inspection planning methods. The HVCMM not only facilitates inspection path planning, but also speeds it up because the operator does not need to slow the probe down when it is approaching an object. Combined visual and force feedback is the best indicator for selecting measurement points.     

An analytic-hierarchy-process based simulation model for implementation and analysis of computer-aided systems

The many successful implementations of computer-aided systems (CAx) have created major advantages for most companies in the competitive world market. In particular, some companies have implemented these systems in order to keep up their competitive power, as computer applications in various fields of production systems are more widely used than before. Unfortunately, these companies have met some problems in their implementation processes, such as a lack of welleducated personnel, in sufficient management support, wrong implementation strategies and techniques, and so on. In order to overcome these problems, in this paper a systematic structure for the implementation and analysis of CAx systems is presented to eliminate--or at least reduce--these kinds of problems. In addition, some techniques, such as the analytic hierarchy process (AHP), benchmarking and simulation approach are used together to make the implementation and analysis studies more effective, easy and applicable for the companies. The objectives of the research are: first, to use the AHP technique for the evaluation of the hardware and software components for a targeted CAx system, secondly, to use a simulation generator integrated with the AHP in order to try the alternatives that are ranked by the AHP study, on a real-life product organization model of a company, until a model is found that provides the best performance values as determined by the company's management.     

The Utility of Signal-Detection Theory in the Analysis of Industrial Inspector Accuracy

In an experimental study of inspector accuracy utilizing industrial electronics inspectors as subjects, a visual, subject-paced task requiring a “yes-no” response was used. The results are thought to be generally applicable to visual inspection tasks, but may not be applicable in an inspection task requiring measurement, as in machine parts inspection. The major conclusion of the research is that signal-detection measures are more useful in performance evaluation than are other available measures, because they not only relate performance to payoff, but indicate the magnitude and direction of improvement required.     

Computerized roundness inspection

Computerized visual inspection systems are increasingly being considered and implemented as an alternative to manual inspection and manual gauging in manufacturing systems. Although computer vision systems and image processing have received much attention in the past, statistically powerful, yet computationally efficiency methods still remain to be developed to process the visual information to make computerized inspection systems cost effective. This study investigates the case of inspecting round production parts for shape and size. The statistical properties of the out-of-roundness measurement procedure are investigated. Real-time implementation considerations are discussed.     

组织机构代码证书年检制度改革探讨

本文针对代码年检制度的一些不足,尝试通过统一代码年检规范和代码年检流程再造等改革手段来提高代码数据的时效性和准确性,以实现组织机构代码信息的完整、可靠,提高年检电子档案扫描的覆盖率和正确率,最终达到减少组织机构代码年检的社会成本,实现效益与成本兼顾的最佳状态。     

YP13型装封箱机缺条视觉检测系统设计

目的解决YP13装封箱机生产过程中产生的箱装烟条缺条缺陷产品不能有效被检测及剔除的问题。方法设计一种新型YP13装封箱机缺条视觉检测系统,通过对其关键技术的研究,综合集成工业相机及触发脉冲信号的安装、支架设计的安装、动态图像的采集、PLC控制程序的设计等,实现箱装烟条缺条缺陷产品的高效检测及准确剔除。结果该视觉检测系统实施后,箱装烟条缺条缺陷产品检测剔除率≥99.9%,误检率≤0.02%。结论该视觉检测系统能提升产品质量、降低物耗,可推广应用于行业内包装规格为每件2×25条或25条的装封箱设备上。     

Impact of inspection errors on the performance measures of a general repeat inspection plan

Multi-characteristic critical components exist in many systems. Such components may be a part of an aircraft, space shuttle or a gas ignition system. An inspection plan for such components has been proposed in quality control that deals with several types of classification errors made by the inspector. In this paper, performance measures for this plan are defined and the statistical and economic impact of the several types of inspection errors on these measures is investigated. The impact of the errors is studied by conducting sensitivity analysis on the errors utilizing computer software which implements an algorithm that determines the optimal parameters of the model of the plan. The behaviour of the performance measures upon variation in the levels of errors is investigated. The results indicate that these errors have a considerable effect on the performance measures of the inspection plan.     

A knowledge-based system for solving multi-objective assembly line balancing problems

This paper presents design-and-development details of a knowledge-based system that solve multi-objective assembly line balancing problems to obtain an optimal assignment of a set of assembly tasks to a sequence of workstations. Assembly line balancing problems arise in high-volume production systems with a significant regularity. The formulation and solutions currently employed by managers and practitioners usually aims at optimizing one objective (e.g., number of work stations or cycle time), thus ignoring the multi-dimensional nature of the overall objectives of the manager. Furthermore, in practice ALBPs are ill-defined and ill-structured, making it difficult to formulate and solve them by mere mathematical approaches. The knowledge-based system multi-objective assembly line balancing approach, presented in this paper, addresses these needs. This paper presents a knowledge-base multi-objective approach to assembly line balancing problems. It demonstrates how such a system can be constructed and how a variety of assembly line balancing methods can be used in a uniform structure to support the decision maker (DM) to formulate, validate the formulation, generate alternatives, and choose the best alternative. Its capabilities include: (1) Elimination of inconsistencies in the problem structure. (2) The use of multi-objective formulation of the problem, (3) A well-designed user-interface, (4) Pursuance of the overall objectives of the manager via a new mechanism, (5) Development of several efficient alternatives, consistent with the user-specified constraint structure, providing the decision maker with a larger number of choices, and, (6) An approach for ranking and prioritizing alternatives consistent with the decision-maker's preferences.     

Loading and control policies for a flexible manufacturing system

An experimental investigation of operating strategies for a computer-controlled flexible manufacturing system is reported. The system is a real one, consisting of nine machines, an inspection station and a centralized queueing area—all interconnected by an automatic material-handling mechanism. The operating strategies considered involve policies for loading (allocating operations and tooling to machines) and real-time flow control. A detailed simulation was employed to test alternatives. The results are different from those of classical job shop scheduling studies, showing the dependence of system performance on the loading and control strategies chosen to operate this flexible manufacturing system. Loading and control methods are defined that significantly improve the system's production rate when compared to methods which were previously applied to the system. Finally, some conclusions are presented concerning the control of these automated systems.     

A decision model for evaluation of flexible manufacturing systems in the presence of both cardinal and ordinal factors

This paper presents a model for evaluating alternative Flexible Manufacturing Systems by considering both quantitative and qualitative factors. The evaluation process utilizes a recently proposed Data Envelopment Analysis (DEA) model, which incorporates both ordinal and cardinal measures, in conjunction with new extensions in DEA. The paper contributes to the body of knowledge in two important ways. First, it provides a new model based on pair-wise comparisons of specific alternatives, which significantly improves the discriminatory power of DEA. The second major contribution is to detail the model's utility in its application for evaluating strategic manufacturing technologies, specifically Flexible Manufacturing Systems. The consideration of both tangible and intangible factors, which is a primary goal in strategic evaluation of systems, is achieved in this methodology. The model is illustrated through an application on a previously reported data set. The analysis of results provide useful insights that include both seller's and buyer's perspectives of system evaluation.