中小企业生产系统重组设计的并行方法

中小企业生产系统需要根据市场环境的变化进行调整与重组设计以实现生产系统与外部环境的协调以及生产系统内部各功能要素的协调。提出一种基于工作地布置的生产系统整体化重组方法。这种方法的特征是基于工作地布置采用循环工作模式和并行工作的方法对生产系统进行整体化设计,从生产系统各功能领域的整体角度讨论中小企业生产系统重组的方法论体系。给出应用这种方法的一个实例。     

本刊投稿导向

1.本刊近期征稿的主要方向 物流系统和供应链管理;企业重组和可重组制造;ERP和MRPⅡ实施;工作研究和工时定额制定;库存的ABC管理及其他;质理管理与6SIGMA:生产系统分析与诊断,等。 2.本刊特别欢迎下列稿件 ·企业主管和IE工程师就上述问题或本企业其他经验撰写的文章;     

制订生产系统重组战略的参与性方法

本文探讨了生产系统重组战略的参与性制订方法，这种方法的核心是为企业员工提供一个展示、讨论和交流自己的见解和主张的平台，通过集思广益对企业生产系统的状况进行分析和提出解决方案，并最终形成各项方案整体协调的生产重组战略。在文章的最后还将介绍这个方法在一个丹麦企业的应用实例。     

快速重组制造系统的构建原理及其应用

快速重组制造系统是一种适应21世纪全球化市场竞争的新型制造系统。提出了基于组态式柔性制造单元组成的陈列式布局的快速重组制造系统的创新结构体系,建立了以生产效益为该系统方案设计和运行决策目标的随机模型,应用排队网络模型和静态马尔科夫工件运送方式得出系统重组时缓冲区容量的优化配置和最优工件运送策略的算法,研制了作为构建快速重组制造系统核心的新颖的组态式柔性制造单元的原型,并给出生产工程中应用所创建的阵列式可重组制造系统的成功案例。     

变风量空调系统整体设计及实施的必要性

通过对变风量(VAV)空调技术的发展及其在我国应用现状的分析,总结我国变风量空调系统整体使用效果不佳的原因,并提出针对性的整体化解决方案,阐述变风量空调系统项目实施过程中多专业配合、整体设计和系统集成调试的重要性.     

灵捷生产系统

我国企业面临变化和不确定的市场环境，要求建立具有快速性、多品种适应性和可重组性三层特性的灵捷生产系统，以抓住市场机遇。本文针对某小型企业的具体情况，设计了一种基于自治单元的混合生产系统。这个方案交少的层次，统一管理生产部门和生产后勤部门；综合动用拉式与推式方法进行生产计划与控制。论文讨论了单元内部的组织机制和可重组性的实现要素。本文对我国中小企业生产重构有一定参考价值。     

对业务流程重组在月生产计划中的应用问题的研究

重点对企业生产计划进行深入研究.在业务流程重组思想的指导下,讨论企业工艺流程的重组.适应中小型企业根据企业内外的各种资源约束来编制月生产计划并指导企业的生产加工,以实现最大的经济效益.     

复合材料结构固化变形预测

针对复合材料结构中广泛存在的固化变形现象,分析并讨论了其产生原因和可能的解决措施.并给出典型复合材料结构元件的固化变形预测规律.结合飞行器复合材料整体化结构的概念,以共固化复合材料加筋板为例,说明了整体化结构固化变形和几何设计参数之间的关系.     

基于工作流的虚拟制造企业生产管理系统的设计与实现

为了解决虚拟制造企业业务流程重组的问题,提出了一种基于工作流技术的虚拟制造企业生产管理系统的设计方法。首先,分析了虚拟制造企业业务流程的特点,阐述了虚拟企业工作流模型的建立,并且利用Petri Nets对工作流的过程模型进行分析;然后,重点阐述了.Net Framework下基于B/S和C/S模式的三层分布式体系结构的PMSVME的设计,并详细阐述了工作流管理模块的设计与实现、系统体系结构及关键技术、工作流程的建立及运行效果。     

基于PLC的涂料机械手系统设计

本设计利用气动枢纽和PLC控制技术，采用整体化的设计思想，充分考虑了软、硬件的特点并进行互补优化。最终实现了蜡模的“涂料——淋砂——涂料——淋砂”的循环工作。经实验证明该系统有一定的应用价值，提高了经济效率。     

Process and production planning for circuit board assembly

Process planning output can be post-processed into criteria for job scheduling decisions in printed circuit board assembly using surface-mount technology (SMT). Artificial intelligence-based techniques used in computerized planning and scheduling systems in other industries can be extended to printed circuit board operations. These techniques include blackboard architectures, object-oriented programming systems, and nonmonotonic reasoning systems. These techniques were used to demonstrate a unique architecture of blackboard systems that communicate via object-oriented messages to arrive at a shop-floor process plan and production schedule. The methodology was specialized to the assembly of printed circuit boards using surface-mounted components in a high-variety/low-volume product mix. The assembly facility was represented as a hierarchical object of product, process, and organizational knowledge. The system of working heuristics was integrated within a prototype environment with the practitioners that assisted in its development. The end result is a good working methodology for system development, implementation, and maintenance by knowledge worker involvement.     

A human task-oriented simulation study in autonomous production cells

Simulation on human tasks has become increasingly important in manufacturing systems’ design, assessment and improvement. In order to evaluate working processes and human factors in autonomous production cells (APCs), a collective analyzis of human-centred simulation approaches in advanced manufacturing systems is carried out, and a human task-oriented simulation methodology is proposed in this paper. Based on the methodology, a comparative simulation study is carried out in a 3D laser welding production cell from the aspects of human task spectrum, human error and occupational requirements. Human task network models of both conventional working process and APC working process are constructed using timed coloured Petri Nets. The evaluation criteria architecture for the simulation is formulated and the respective algorithms and parameters for the criteria are discussed in detail. A simulation program using C++ is developed based on Poses++ Petri Net simulator. The simulation results show some important transitions of system performance and human factors from the conventional production cell to the APC, which can support the decision-making when redesigning the conventional production cells to fit the requirements of APCs.     

A methodology integrating Petri nets and knowledge-based systems to support process family planning

Planning production processes for product families have been well recognised as an effective means of achieving successful product family development. However, most existing approaches do not lend themselves to planning production processes with focus on the optimality of the cohort of a product family. This paper addresses process family planning for product families. In view of the advantages of Petri nets (PNs) for modelling large systems, the potential of knowledge-based systems (KBSs) for solving complex problems and the analogy in between, we develop a methodology by integrating PNs and KBSs to support process family planning. An integrated product–process family structure, called IP²S, is proposed to organise all data pertaining to a product family and the corresponding process family, thereby anchoring planning to one platform. With the IP²S, a formal PN model of process family planning is further developed by integrating the principles of several well-defined PN extensions. Thus, this paper also contributes to visualising the dynamic behaviours and reasoning behind process family planning. The methodology is applied to process family planning for a truck family. The preliminary results demonstrate the feasibility and potential of using the methodology to support process family planning.     

P-graph approach to criticality analysis in integrated bioenergy systems

The use of integrated bioenergy systems (IBS) is a prospective solution to address the emergent global demand for clean energy. The sustainability of IBS compared to stand-alone biomass processing facilities is achieved through integration of process units or component plants via their bioenergy products, by-products, wastes, and common utilities. However, such increased component interdependency makes the resulting integrated energy system vulnerable to capacity disruptions. IBS in particular are vulnerable to climate change-induced events (e.g., drought) that reduce the availability of biomass feedstocks in bioenergy production. Cascading failure due to such supply-side disruptive event is an inherent risk in IBS and may pose a barrier to the commercial-scale adoption of such systems. A previous study developed a risk-based criticality index to quantify the effect of a component’s disruption within integrated energy systems. This index is used to rank the component’s relative risk in the network based on the ripple effects of its disruption. In this work, a novel P-graph approach is proposed as an alternative methodology for criticality analysis of component units or plants in an IBS. This risk-based metric can be used for developing risk management polices to protect critical facilities, thereby increasing the robustness of IBS against disruptions. Two case studies on determining the criticality index of process units in an integrated biorefinery and component plants in a bioenergy park are used to demonstrate the effectiveness of this method.     

A hybrid methodology for enhancing reliability of large systems in conceptual design and its application to the design of a multiphase flow station

This paper presents a hybrid methodology for conceptual design of large systems with the goal of enhancing system reliability. It integrates the features of several design methodologies and maintenance planning concepts with the traditional reliability analysis. The methodology considers the temporal quality characteristic “reliability” as the main objective and determines the optimal system design. Key ideas from several design methodologies, namely axiomatic design, robust design, and the theory of inventive problem solving, have been integrated with the functional prioritization framework provided by reliability-centered maintenance. A case study of the conceptual design of a multiphase pumping station for crude oil production is presented. The methodology provides a new design tool for determining system configurations with enhanced reliability taking into account maintenance resources and variability.     

System dynamics analysis for an Internet-of-Things-enabled production logistics system

A production logistics system is often subject to high operational dynamics due to large working areas, frequent resource interactions, long operation periods and intensive human involvement. Researchers have applied system dynamics to design the structure of statistically robust systems which accommodate common dynamics. Yet this approach begins to lose its feasibility because dynamics anticipation and statistics are becoming more difficult in ever more competitive markets and adjustments to system structure typically incur high costs. In response, this study explores how a robust information structure can be designed and real-time control schemes for controlling the dynamics inherent to real-life systems applied. Motivated by the wide application of industrial Internet-of-Things (IoT) systems, this paper investigates the typical production logistic execution processes and adopts system dynamics to design cost-effective IoT solutions. The internal and external production logistic processes are first investigated separately. Using sensitivity analysis, the optimal IoT solutions are evaluated and analysed to provide guidance on IoT implementation. Internal and external production logistic processes are then combined into an integrated structure to offer a generic system dynamics approach. This research does not only enhance the use of system dynamics, but also presents a quantitative IoT system analysis approach.     

Dynamic failure analysis of renewable energy systems in the remote offshore environments

For effective integrity management of marine renewable energy systems in the dynamic and uncertain ocean environments, understanding the failure dynamics is crucial. The cost of investment in marine/offshore renewable energy infrastructures and the associated cost due to failure and loss of energy production necessitate a predictive monitoring methodology that is dynamic and adaptive. This paper presents an integrated multi-state pure-birth-pure-death Markovian-net profit value model for the offshore turbine subsystem failure analysis and its cost-based consequences. The integrated model captures the offshore turbine subsystem's dynamic failure states and its economic implications due to the cost of energy loss and downtime for the period under consideration. The model applies a phase-type exponential distribution to describe the monotonic state of failure. The methodology is demonstrated with an offshore wind turbine gearbox, and it captures the dynamic state of the system and its failure mechanisms. The cumulative effect of the subelements deterioration decreases the gearbox performance by over 35% within the first 2 years of operation.     

An integrated fuzzy approach for information technology planning in collaborative product development

Collaborative product development (CPD) processes are generally based on technological infrastructures. Various information technologies (IT) are proposed every day to facilitate collaboration, integration, co-design and co-development processes. In this highly uncertain environment, a systematic methodology is essential to plan the IT infrastructure needed to start and maintain a collaborative process. This study offers an integrated IT planning methodology combining fuzzy quality function deployment, fuzzy axiomatic design and fuzzy rule-based systems. The methodology is tested in a CPD case and the outcome presents an improvement path for IT for each of the collaborative parties.