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1.
This paper deals with improving the lead-time performance of a large crystal manufacturer that uses a state-of-the-art commercial Enterprise Resource Planning system. Since the company encountered some limitations of the standard production planning and control (PPC) system it sought for improvements by implementing an order release mechanism based on workload control (WLC). WLC employs certain rules for releasing orders in order to maintain a certain level of work in process to achieve a certain utilisation of the production system and thus control the flow times in order to meet the required due dates of the orders. We describe the successful implementation of an order release mechanism based on the WLC concept in this make-to-stock company. The paper describes the implemented order release mechanism, the implementation process and its impact on the company’s performance. We show that the core function of WLC – the order release mechanism – can be integrated successfully into an existing PPC system. Furthermore, this study highlights the applicability of WLC to a wider range of companies, especially to make-to-stock manufacturers.  相似文献   

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The pharmaceutical industry in China makes an important contribution to the national economy. However, the associated pollution problems cause gradual deterioration of the environment and impact adversely on the local community. Cleaner production (CP) technology, an effective way to reduce waste emission and save resources, has been widely employed in the pharmaceutical industry in the developed countries. Such technologies have been applied in a number of factories in China, although there is no integrated assessment and implementation procedure for implementing CP technologies in pharmaceutical plants. To solve such problems, a series of CP options are proposed and assessed here. CP is a powerful tool for decreasing waste production, limiting environmental pollution and natural resource depletion. Moreover, the return on investment in CP is quick, so it would seem that CP activities should be very much in demand by enterprises. Reality is less optimistic: frequently only limited interest is expressed, even after an explanation; business people hesitate to become actively involved. The processes in the pharmaceutical production industry produce a vast amount of waste, including wastewater with high concentrations of organic substances (the principal component), solid waste, and organic off-gas. To solve such problems, a series of CP options are proposed and assessed in this study. Having consideration to environmental impacts and economic efficiency, four groups of medium/high cost CP options were screened in an integrated assessment. To verify the proposed options, a case study was conducted in Degussa Luyuan, Northeast China. The characteristics of resource consumption and waste emission during the production process were identified. The proposed options were evaluated according to different aspects. An integrated CP system based on the proposed options was designed and then implemented in the factory. In three years of practical use, the productivity and quality of alcohol product were improved, with a reduction in waste and pollution and a marked increase in water/energy savings. This study provides theoretical and practical support for the extensive application of CP technologies and sustainable development in China’s pharmaceutical industry. These methods include ways to clean up production that are incorporated in the process design, reforming present production technologies, updating the equipment, exploiting new producing flowcharts, using cleaner energy, building recycling into the manufacturing process, recycling waste, enhancing management, developing environmental protection technology, and ensuring satisfactory end-of-pipe disposal.  相似文献   

4.
This study aims to observe the researchers’ behavior in Iranian scientific databases to determine the research gaps and priorities in their field of research. Text mining and natural language processing techniques were used to identify what researchers are looking for and to analyze existing research works. In this paper, the information about the behavior of researchers who work in the field of environmental science and existing research works in the Iranian scientific database are processed. The search trends in all areas are evaluated by analyzing the users’ search data. The trend analysis indicates that in the period of February 2013 to July 2015, the growth of the researchers’ requests in some domains of the environment such as Industry, Training, Assessment, Material, Water and Pollution was 1.5 up to 2 times more than the overall requests. A Combination of the trend analysis and clustering of queries led to shaping four priority zones. Then, the research priorities for each environmental research area were determined. The results show that Training, Pollution, Rangeland, Management and Law are those domains in the environmental research which have the most research gaps in Iran, but there are enough research in Forest, Soil and Industry domains. At the end, we describe the steps for the implementation of a decision support system in environmental research management. Researchers, managers and policy makers can use this proposed “research demand and supply monitoring” system or RDSM to make appropriate decisions and allocate their resources more efficiently.  相似文献   

5.
Many factors in the current scenario have influenced manufacturing organisations to have a competitive edge by concentrating on entire supply chains. Sourcing decisions are one of the strategic decisions because they enable companies to reduce costs and improve profit figures. The main task in sourcing is vendor selection. Recent challenges such as shortened product life cycle, just-in-time environment, and the importance of strategic partnerships in upstream chains always influence companies to prioritise vendor selection. In addition, outsourced parts and components account for a significant contribution in the cost of finished goods. Thus evaluating and selecting the right vendor is the key to business. Vendors are selected merely on the basis of cost factors in the traditional approach. However, companies eventually have understood that their approach which emphasises costs as the sole criterion is inefficient and needs to be changed. To deal with the complex process of vendor evaluation, multiple criteria decision-making techniques have evolved. This study presents the integrated approach of multiple multi criteria decision making (MCDM) techniques such as fuzzy logic, strength-weakness-opportunity-threat (SWOT) analysis, and data envelopment analysis. The efficacy of the proposed approach is evident from the case study of an automotive component manufacturer involving 20 vendors, comprising of pre-qualification by fuzzy SWOT and final selection by DEA.  相似文献   

6.
Bidding-based negotiation schemes play a major role in multi-agent manufacturing systems research. Despite some concerns with message congestion, researchers have been proposing and studying negotiation schemes based on the contract net protocol (CNP). On the other hand, research in robotics has considered a variant of CNP based on publish-subscribe messaging designed for multi-robot coordination. A distinct feature of this variant involves distributing the bid evaluation and selection functions among robot agents. This paper discusses our adaptation of this design variant for multi-agent manufacturing systems and examines its performance implications. Using discrete-event simulation, we study how the adapted CNP design can help address the message congestion problem by cutting down on negotiation slack time. Our case study results show that it can enhance the resilience of the agent negotiation process to message congestion, thereby contributing to the overall performance of a multi-agent manufacturing system.  相似文献   

7.
A livelihood strategy is an organized set of lifestyle choices, goals and values, and activities influenced by biophysical, political/legal, economic, social, cultural, and psychological components. The evolution of livelihood strategies was examined in Molas, a coastal village in North Sulawesi province, Indonesia, near the famous coral reefs of Bunaken National Park. Molas was selected to assess how these strategies, especially those of farmers and fishers, are affected in the anticipation stage of tourism development. Study results indicate that documenting the historical evolution, and present and emerging patterns, of livelihood strategies is an essential foundation for successful development and implementation of community-based strategies for environmental planning and management.  相似文献   

8.
For a long time, rankings overused in evaluating Chinese universities’ research performance. The relationship between research production and research quality hasn’t been taken seriously in ranking systems. Most university rankings in China put more weight on research production rather than research quality. Recently, the developmental strategy of Chinese universities has shifted from ‘quantity’ to ‘quality’. As a result, a two-dimensional approach was developed in this article to balance ‘quantity’ and ‘quality’. The research production index and the research quality index were produced to locate research universities (RU) from Mainland China, Hong Kong (HK) and Taiwan (TW) in the two-dimensional graph. Fifty-nine RU were classified into three categories according to their locations, which indicated the relevant level of research performance. University of Hong Kong, National Taiwan University, Tsing Hua University and Peking University appeared to be leading universities in research performance. The result showed that the mainland universities were generally of higher research production and lower research quality than HK and TW universities, and proved that the merging tides of Chinese universities enlarged their research production while causing a low level of research quality as well.  相似文献   

9.
The manufacture of sugar from crushed sugar-cane involves processing through a number of stages. The yield of crystalline sugar per unit of processed juice depends on a variety of process parameters. Increased yield is also related to the determination of a suitable mix of in-process ingredients. In this paper a case study is presented where the use of product mix has been made. The product mix in this case is arrived at by considering the profit motive of the entrepreneur and keeping in view the constraints imposed by the processing times at various stages and the capacities of the equipment at each stage. The problems of implementation of the proposed product mix were then explored and a suitable production schedule has been suggested taking into consideration certain important constraints imposed by the Indian environment.  相似文献   

10.
In this article, a three-step method, proposing how small- and medium-sized enterprises (SMEs) can improve the environmental performance in their supply chain, is presented. The method is based on (1) an assessment of their products, (2) identification of critical processes that should be improved, and (3) identification of actors in the supply chain that should be focussed upon not only based on environmental performance, but also based on the abilities that the end producer has to influence them. This article is exemplified with a case study of furniture production in Norway. The case shows that the potential for improvement of processes under direct control by the end producer is limited. However, the three steps, as a whole, show how an SME with limited resources and supply chain power can identify key actors in the supply chains for further improvements, based on a potential for improvements of environmental performance and the possibilities that the end producer has to impose improvements.  相似文献   

11.
This paper presents a new approach of genetic algorithm (GA) to solve the constrained optimization problem. In a constrained optimization problem, feasible and infeasible regions occupy the search space. The infeasible regions consist of the solutions that violate the constraint. Oftentimes classical genetic operators generate infeasible or invalid chromosomes. This situation takes a turn for the worse when infeasible chromosomes alone occupy the whole population. To address this problem, dynamic and adaptive penalty functions are proposed for the GA search process. This is a novel strategy because it will attempt to transform the constrained problem into an unconstrained problem by penalizing the GA fitness function dynamically and adaptively. New equations describing these functions are presented and tested. The effects of the proposed functions developed have been investigated and tested using different GA parameters such as mutation and crossover. Comparisons of the performance of the proposed adaptive and dynamic penalty functions with traditional static penalty functions are presented. The result from the experiments show that the proposed functions developed are more accurate, efficient, robust and easy to implement. The algorithms developed in this research can be applied to evaluate environmental impacts from process operations.  相似文献   

12.
In order to retain a certain level of production in Norway,suppliers to the Norwegian maritime industry need to lower their production costs.Automation is generally an effective way of achieving this in standardized high-volume,low variety production.However,manufacturing companies in the Norwegian maritime industry typically supply capital-intensive,advanced and customized products in low volumes.In this engineer-to-order production situation,manual labor is traditionally preferred over automation.Nonetheless,such companies increasingly automate parts of their production.This paper presents a case of a supplier that has chosen to automate its welding operations,the implications and determinants of this decision.  相似文献   

13.
Chemical components of airborne volatile organic compounds (VOCs) released from a wastewater treatment system of the tapioca industry were identified. Quantitative analysis of the concentrations and the emissions of each chemical were evaluated taking into consideration the difference in atmospheric turbulence over the surface of the wastewater during the day and the nighttime periods. The chamber experiments were performed on-site in order to reflect actual environmental characteristics of the study area. Chemical concentrations were analyzed following the U.S. EPA TO-15 Standard Method. Emissions of each compound were calculated using the box model scheme. It was found that acetaldehyde and acetone were two major compounds of released airborne VOCs from the wastewater treatment system of the tapioca industry. Due to its high organic content, the wastewater treatment facilities of this type of factory generally caused the odor problem to its surrounding communities. These data were then used to evaluate the success of implementing the Clean Development Mechanisms project in this industry. Reduction in the affected area from odor by improving the wastewater treatment system from opened lagoons which is the type of common practice in most of the tapioca factories in the developing countries to the modified covered lagoons was evaluated. These results supported the theory of the co-benefit of managing both local environmental problems and reduction of greenhouse gas emissions from the implementation of cleaner technology in the agro-industry. This methodology can be applied to reveal and quantify the success of other green efforts particularly in the agro-industry businesses.

Graphical abstract

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14.
Since its beginning, lean manufacturing has built a worldwide reputation based on results related to production improvement and cost reduction in several companies. This management philosophy focuses on customer value creation through the elimination of production wastes. Lean methods and techniques have spread their scope from the automotive industry to a wide range of industries and services. This article presents a case study that describes the use of the lean tool value stream mapping in the production process of automotive parts for a major automotive company. At the beginning of the project, relevant data from the process were collected and analysed. Subsequently, the initial process was mapped, the related wastes were identified, and then future processes were mapped and financial results were estimated. The proposals were presented on kaizen meetings, the action plan was discussed and the decision regarding which option to choose was taken. Consequently, the Cycle Time and the level of the workforce were reduced, the process was improved and savings were obtained.  相似文献   

15.
The choice between repairing and replacing a defective piece of equipment is an economic decision that is faced by all maintenance managers, including housing estate managers. Such decisions need to be made within the limits and constraints set by maintenance expenditure budgets and by manpower availability. Our particular problem is concerned with the development of a maintenance policy for a residential estate of the Hong Kong Housing Authority. Our approach is to treat the numerous housing systems as a portfolio and to exploit flexibilities in performing or delaying the repair/replacement of these systems. The cost of a repair/replacement plan for the portfolio is formulated as an integer programme and genetic algorithms (GAs) are employed to generate optimal and sub‐optimal solution plans. The novel features of the approach are the model developed and use of GAs in this particular optimization context. The results and discussion of the case study will help practitioners to better understand the difficulties involved in collecting relevant cost data and in formulating repair/replacement plans for a group of buildings. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

16.
This paper examines the patent grant rate of Korea and Taiwan by using the country-level patent statistics of Korea, Taiwan and USA during the period of 1988–1998. The patent grant rate means the rate of US patent grants to the applications filed in USA during the investigated years. To measure the grant rate, a model was developed for the methodological procedure. In the framework of the model, the process of patent dynamics in these countries shows different patterns. The financial crisis of Korea in 1998–1999 influenced the number of domestic patent applications by Koreans, resulting in the rapid decrease. The US patent application rate by Koreans, however, was not affected, keeping the average rate of applications at 7.5% of the Korean applications during the investigated period. The rate of US patent grants by Koreans in the early 1990s dropped, which can be explained by the change of patent strategy of Samsung Elec. Co. Ltd.Taiwan, on the other hand, had filed 160% more US patent applications than its own domestic applications. The authors suggest that this is attributable to some US patent applications corresponding to Taiwanese domestic applications for utility models, and that this may be a factor in the lower rate of Taiwanese US patent grants (average 53.4%) than that of Koreans (average 66.3%). The rate of US patent grants by Taiwanese has constantly increased, while that for Koreans has fluctuated; the authors conjecture that this implies that Taiwanese patent management for the US patents has improved.  相似文献   

17.
This paper evaluates the importance of jointly conducted research versus national, when neighbouring countries are trying to study a topic of their mutual interest. The chosen topic was the shared ocean or lake basin. The number of non-mutual and mutual articles in the period 1999–2008 for seven pairs of neighbouring countries was analysed by extracting published articles and citations from the Web of Science database. It was found that mutual articles have generally better visibility than the non-mutual articles, valid even for large and developed countries. Also, the percentage of self-citations in the mutual articles is much lower than in the non-mutual ones. However, the citations of the non-mutual articles are influenced by the development of the country or, in some cases, by the development of the countries in which researchers from a certain country are presently working (this applies strongly to the Eastern Europe countries).  相似文献   

18.
Degradation experiments are usually used to assess the lifetime distribution of highly reliable products, which are not likely to fail under the traditional life tests or accelerated life tests. In such cases, if there exist product characteristics whose degradation over time can be related to reliability, then collecting ‘degradation data’ can provide information about product reliability. In general, the degradation data are modeled by a nonlinear regression model with random coefficients. If we can obtain the estimates of parameters under the model, then the failure‐time distribution can be estimated. In order to estimate those parameters, three basic methods are available, namely, the analytical, numerical and the approximate. They are chosen according to the complexity of the degradation path model used in the analysis. In this paper, the numerical and the approximate methods are compared in a simulation study, assuming a simple linear degradation path model. A comparison with traditional failure‐time analysis is also performed. The mean‐squared error of the estimated 100pth percentile of the lifetime distribution is evaluated for each one of the approaches. The approaches are applied to a real degradation data set. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

19.
Process management and innovation arguably remain among the concepts under focus of recent researches since there is no significantly outstanding method to measure and monitor the level of innovation in the manufacturing processes over a particular time period taking the fundamental activities of manufacturing processes into account. Although there are various studies relevant to process improvement, manufacturing processes are not focused on in the literature. This paper presents a novel performance indicator, called degree of process innovation, for monitoring and measuring innovation in manufacturing processes based on the four most important components among the fundamental activities of a manufacturing system. The components are namely Average Labour Utilisation, Cumulative Bottleneck Ratio, Unit Production Time and Unit Production Cost. The idea behind this approach has flourished on the basis of an indicator proposed in the literature to measure the general organisational improvements. The scope of that indicator has been narrowed down to manufacturing processes to accurately reflect the state of the manufacturing processes. The proposed approach has been verified with a case study in manufacturing industry, where each of the four sub-indicators was calculated based on the data provided and aggregated into the degree of process innovation. The innovation degree is successfully indicated.  相似文献   

20.
运用机器视觉技术和机器人技术设计并实现了一种识别、分拣盒装香烟的系统,以提高识别准确率和分拣效率。该系统通过USB摄像头采集烟盒图像信息,从烟盒的特征检测入手,利用Matlab工具对香烟条形码、烟盒颜色和字迹字符三个方面进行处理分析,识别出真伪香烟,并随即通过控制机器人手爪对识别出的香烟进行分拣。  相似文献   

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