Six sigma as a business process management method in services: analysis of the key application problems

Apart from being applied in production, Six Sigma has grown considerably in importance as a business process management (BPM) method in services. The transfer of the method from production to service applications does, however, pose problems which affect the success of implementing Six Sigma as a BPM method in services. For a successful application of the Six Sigma method in services it is helpful to know these possible problems in order to be able to avoid them and to achieve the goals of Six Sigma improvement projects. In addition from a theoretical view knowing the problems is a first step for further development of the Six Sigma method. Therefore, the present article deals with the following questions: which key problems regarding the application of Six Sigma in services are mentioned in the literature and which phases of the Six Sigma cycle can they be assigned to? The existing literature on this subject is reviewed and a qualitative content analysis of its contents is presented. Additionally, a survey based on the problems found in the literature is conducted to compare theory and practice. The evaluation of the results shows, on the one hand, that to date the problems of the application of Six Sigma in services have little been dealt with. On the other hand the evaluation provides a survey of the problems structured in accordance to the phases of the Six Sigma cycle. Thus, the present paper offers new findings as regards the state-of-the-art of the Six Sigma method.     

Blending CMM and Six Sigma to meet business goals

Tata Consultancy Services (TCS) blended Six Sigma concepts with the various SW CMM key process areas, thereby creating a quality management system. This helped TCS improve its customer focus and sustain process improvement initiatives by explicitly linking them to business goals. The TCS team implemented the QMS on the lines of Level 2 and 3 requirements of SW CMM, using Six Sigma concepts to reinforce quantitative process and product measurements and analysis, process improvements for defect prevention, and process optimization. This article describes TCS's approach, highlighting the benefits gained by blending Six Sigma and CMM to provide quality deliverables to its customers.     

Design for Six Sigma through collaborative multiobjective optimization

This paper presents a global methodology for designing product for Six Sigma. First, we combine a feasibility-modeling technique with an interactive multiobjective algorithm taking into account the decision maker’s preferences (IMOP) to generate several Pareto-optimal solutions that maintain a probability of constraint satisfaction. These solutions are called reliable Pareto-optimal solutions.The solutions found by the algorithm fulfill as much as possible the decision makers’ requirements. Second, we develop a procedure for choosing a solution for implementation from among the reliable Pareto-optimal solutions generated by the algorithm. This procedure is based on the robust design and philosophy of Six Sigma. Finally, the critical characteristics are identified to help the managers develop the manufacturing system and its related control plans in order to achieve quality products. The proposed methodology is applied to vehicle crash-worthiness design optimization for side impact with structural weight and front door velocity under side impact as objectives.     

六西格玛方法在过程改造中的应用简介

介绍了六西格玛(6σ)的概念、基本评价指标及其开发的DMAIC流程的含义与主要分析工具,并介绍了六西格玛法在过程优化中的应用。该过程是一生产己内酰胺的连续过程,6σ利用统计学工具如量规分析、方差分析对过程的各个生产单元进行分析,找出各个生产单元的关键输入变量和输出变量及其关系,确定影响产品产量的瓶颈,包括操作条件和低效或陈旧的仪表与设备,并用实验设计验证以上分析结果,最后消除瓶颈,达到提高产量的目的。     

A systematic methodology for the creation of Six Sigma projects: A case study of semiconductor foundry

Nowadays, Six Sigma has been widely adopted in a variety of industries in the world and it has become one of the most important subjects of debate in quality management. Six Sigma is a well-structured methodology that can help a company achieve expected goal through continuous project improvement. Some challenges, however, have emerged with the execution of the Six Sigma. For examples, how are feasible projects generated? How are critical Six Sigma projects selected given the finite resources of the organization? This study aims to develop a novel approach to create critical Six Sigma projects and identify the priority of these projects. Firstly, the projects are created from two aspects, namely, organization’s business strategic policies and voice of customer. Secondly, an analytic hierarchy process (AHP) model is implemented to evaluate the benefits of each project and; a hierarchical failure mode effects analysis (FMEA) is also developed to evaluate the risk of each project; and from which the priority of Six Sigma projects can be determined. Finally, based on the project benefits and risk, projects can be defined as Green Belt, Black Belt, or others types of projects. An empirical case study of semiconductor foundry will be utilized to explore the effectiveness of our proposed approach.     

Six sigma for software

Six Sigma concepts are increasingly penetrating software engineering literature and practice. But exactly what Six Sigma is and how you apply its concepts remains unclear. To make sense of the Six Sigma movement, this paper looks back to the origins and implications of its dominant predecessor, total quality management.     

基于Verilog-A的Sigma Delta系统行为级建模

介绍Verilog-A设计语言的特点,基于Sigma Delta系统介绍分级设计思想.分析开关电容型Sigma Delta调制器的非理想特性,主要包括时钟抖动、开关热噪声、运放增益、摆率等.在建立各自噪声模型的基础上,基于Verilog-A对二阶Sigma Delta系统行为级完整建模,通过仿真结果的比对,验证Verilog-A建模,总结其可准确预测指标并在一定程度上有效地削减仿真时间的优点.     

The Integration of TRIZ with Other Ideation Tools and Processes as well as with Psychological Assessment Tools

When TRIZ is introduced into an organization setting, it invariably encounters a host of processes and tools already in place. These can include enterprise tools such as Six Sigma, Design for Six Sigma (DFSS), QFD and Lean Manufacturing. It is fairly easy to combine TRIZ problem‐solving and technological forecasting with these processes and tools, because most of these enterprise tools are problem‐identifying processes that couple easily with the strong problem‐solving capabilities of TRIZ. What is more difficult is to integrate TRIZ thinking with other psychologically based creativity and assessment tools. Users and trainers for these various tools tend to be very protective about each process and do not spend sufficient time thinking about ways to integrate the best of all tools. Organizations also frequently use psychological assessment tools to assist employees in career development, but they are seldom used in a proactive way to improve group problem‐solving. These assessments can be used proactively within the use and implementation of TRIZ. This paper will review suggested ways to effectively integrate TRIZ innovation and problem‐solving principles with these other tools.     

Image-processing procedures for quality estimation in production of elastic foamy materials

We present a system for estimating the quality of polyurethane foam, which is able to measure the apparent density and mean size of the cell. The system consists of a flatbed scanner of high resolution, an electronic balance, and a personal computer. We present the new way for measuring the sample volume using six nonorthogonal projections and adapt the marker dividing line algorithm for cell segmentation in the scanned image. We examine an approach for determining the efficiency of the image-processing system operating as a measuring system on the basis of the Six Sigma method.     

一种基于模型的输出反馈网络化控制系统

提出一种基于模型的输出反馈网络化控制系统.其主要思想是通过引入对象的输入输出模型和缓存器来克服网络造成的信息反馈不及时.该系统在不能获得反馈信息的时候,可以利用对象模型的输出值近似代替对象的输出值计算控制量,而在网络通畅时刻则利用对象输出计算控制量并刷新模型.给出了具体的算法,利用仿真示例验证了算法的有效性.     

Intelligent fault-tolerant system of vibration control for flexible structures

This paper describes an intelligent fault-tolerant control method for vibration control of flexible structures. We consider a case where the fault phenomena of the control system for flexible structures can be treated as a change of system parameters. Therefore, the adaptive control method can be applied to a vibration control system for flexible structures with a fault. In this paper, a neural network (NN) adaptive control system is used to compensate for the change in the parameters of a plant with a fault. When the characteristics of the plant and of a nominal model have been agreed by a NN adaptive control system, the control method designed for the nominal model, such as decoupling feedback control or linearizing feedback control, can be used even if the change in the system parameters has been caused by a fault. To confirm the effectiveness of the proposed fault-tolerant control method, the simulational results from a 5-link robotic arm are shown at the end of the paper. This work was presented, in part, at the Fourth International Symposium on Artificial Life and Robotics, Oita, Japan, January 19–22, 1999     

Computer aided control system design applied to milk drying plants

This paper reviews a computer aided control system design facility that has been used to develop a set of control systems that have been implemented on a pilot scale industrial process. The facility caters for a broad range of control situations including those with interactions, time delays and disturbances. Online interactive graphics is used as a design aid for the identification of plant dynamics and for the assessment of control system performance. Control systems may be developed systematically to be structured in a hierarchical configuration on the plant. Particular applications to the plant, an evaporator and a spray drier, are discussed in detail.     

NETWORK-6000系统故障分析处理

本文介绍了钱清电厂分散控制系统NETWORK-6000在运行过程中发生的控制器、网络、工控机等故障现象,并针对性进行分析和处理,以及在处理过程中需要注意的地方,为同类型控制系统的检修维护提供借鉴。     

Continuous improvement of knowledge management systems using Six Sigma methodology

Knowledge retrieval is a decisive part of the performance of a knowledge management system. In order to enhance retrieval accuracy, an effective performance evaluation mechanism is necessary. Nowadays, there is not a standard evaluation framework for knowledge retrieval evaluation, because the evaluation set up is still technology-dependent, focusing on specific elements of the search context. The laboratory-based evaluation is not suitable to evaluate the knowledge retrieval process, since knowledge is dynamic, constantly changing and evolving. Besides, ambiguous query is also an important factor for the performance of knowledge retrieval systems. In order to improve the performance of knowledge retrieval, this paper proposes an evaluation mechanism using Six Sigma methodology to help developers continuously control the knowledge retrieval process. Specifically, this study involves the following tasks: (i) proposes a general knowledge retrieval framework based on the analysis result of knowledge retrieval, (ii) designs the knowledge retrieval evaluation framework using Six Sigma's Define-Measure-Analyze-Improve-Control (DMAIC) process and (iii) develops the related technologies to implement the knowledge retrieval evaluation mechanism. The knowledge retrieval evaluation mechanism allows system developers to maintain the knowledge retrieval system with ease and meanwhile enhance the accuracy.     

火力发电厂主油泵变频控制系统改造

油泵控制系统是电厂的辅机设备控制系统的重要组成部分,采用传统的继电器控制的油泵系统,机械磨损和耗能比较严重;并且由于继电器布线复杂,不利于系统稳定运行和维护。本文采用西门子系列PLC对油泵控制系统进行改造,经过一段时间的运行,系统的可靠性和稳定性得到较大改善。     

Indirect adaptive control of a two-wheeled vehicle with low-resolution input and output

The Programmable Logic Controller (PLC) is widely used in the industrial world, e.g. in manufacturing, chemical processing, materials handling, etc. The PLC-based control system can be regarded as a control system with low-resolution inputs and outputs. This paper presents a sophisticated control policy which can enhance the control performance for such a class of control system even if the complete information of the plant is not available. In particular, the case of existing uncertainty or perturbations in the input matrix is addressed. The key contribution of this paper is to clarify the identifiability condition for parameters included in the input matrix from measured low-resolution inputs and outputs. This investigation leads to the development of an indirect adaptive control policy with low-resolution inputs and outputs. Finally, the proposed indirect adaptive control policy is applied to the line-following control of a two-wheeled vehicle and its usefulness is demonstrated through experiment.     

Integrated FDD system for valve stiction in a paperboard machine

The performance of a modern industrial plant can be severely affected by the performance of its key devices, such as valves. In particular, valve stiction can cause poor performance in control loops and can consequently lower the efficiency of the plant and the quality of the product. This paper presents an integrated FDD system for valve stiction which employs various FDD methods in a parallel configuration. A reliability index was integrated into each method in order to estimate their degree of influence in the final diagnosis of the system. Each method and the integrated system were tested using industrial data.     

用于安全级专设功能测试的网络化测试系统设计

为验证核电站数字化仪控系统安全级的专设功能,本文提出了一种基于网络的自动化测试系统,重点阐述测试系统的设计,包括网络搭建、通讯实现、测试软件设计等,并举例简述了该系统在CPR1000堆型核电站安全级专设功能测试中的应用.网络化测试系统的使用,实现了核电站数字化仪控系统的闭环测试,能够实时监视测试过程并自动生成删试报告,提高了数字化仪控系统集成测试的效率与质量,降低了测试成本.     

Application of neural networks to temperature control in thermal power plants

In a thermal power plant with once-through boilers, it is important to control the temperature at the middle point where water becomes steam. However, there are many problems in the design of such a control system, due to a long system response delay, dead-zone and saturation of the actuator mechanisms, uncertainties in the system model and/or parameters, and process noise. To overcome these problems, an adaptive controller has been designed using neural networks, and tested extensively via simulations.

One of the key problems in designing such a controller is to develop an efficient training algorithm. Neural networks are usually trained using the output errors of the network, instead of using the output errors of the controlled plant. However, when a neural network is used to control a plant directly, the output errors of the network are unknown, since the desired control actions are unknown. This paper proposes a simple training algorithm for a class of nonlinear systems, which enables the neural network to be trained with the output errors of the controlled plant. The only a priori knowledge of the controlled plant is the direction of its output response. Due to its simple structure and algorithm, and good performance, the proposed controller has high potential for handling difficult problems in process-control systems.     

控制能量约束时不稳定过程最优控制与仿真

在最优控制问题的研究中,工业过程控制领域中不稳定系统的控制难度比较大,且在许多控制系统设计中控制能量可能成为重要的性能指标。对控制能量存在约束时不稳定过程的最优控制问题进行了研究与仿真,优化问题的难点在于性能指标的表示与最小化。首先基于不稳定过程的互质分解,由敏感度函数和控制敏感度函数定义了一个包含跟踪误差和控制能量在内的性能指标,采用谱分解最小化该性能指标,从而为不稳定系统导出了一种最优的控制器设计方法,可使系统获得最优的控制性能。仿真结果进一步说明了方法的有效性。