Formulation of Measurement Sampling Plan for Small and Medium Batch Products in Supply Chain

The article studies the supply chain of suppliers and manufacturers, considering the overall benefits of the supply chain, the measurement sampling plan is the small batch sampling plan with the smallest amount of sampling and the strongest discriminative ability. If the quality characteristic data is a measurement value, and the inspection workload is large and the inspection cost is high, it is recommended to adopt the measurement sampling plan based on the Laplace distribution. On the premise of ensuring quality, try to reduce the number of inspected samples as much as possible to reduce the workload and cost of inspection.

Development of Two Highly-Efficient and Innovative Inspection Schemes for PSC Inspection

Port state control (PSC) inspection contributes a lot to improving maritime safety and protecting the marine environment. After selecting the ships coming to a port for inspection, one critical challenge faced by the PSC authorities is deciding what deficiency items should be inspected and what the inspection sequence of these items is. To address this problem, two innovative and high-efficient PSC inspection schemes describing specific PSC inspection items and sequence are proposed for the inspectors’ reference when time and resources are limited, especially when there are difficulties in estimating the possible deficiencies in advance. Both schemes take the occurrence probability, inspection cost, and ignoring loss of each deficiency item into account. More specifically, the first inspection scheme is based on the occurrence probabilities of the deficiency items in the whole data set, while the second scheme further considers the correlations among the deficiency items extracted by association rules. The results of numerical experiments show that the efficiency of the two proposed inspection schemes is 1.5 times higher than that of the currently used inspection scheme. In addition, the second inspection scheme performs better than the first inspection scheme, especially with inspecting ships with no less than five deficiency items and limited inspection resources.

Game Research on Coal Mine Workers’ Off-Post Behaviors

In order to seek for causes and solutions of off-post behaviors of coal miners, static and evolutionary games were utilized on the basis of an established strategy simulation model between coal mine enterprise and coal miners. These games were used to determine the revenue matrix of two game parties given off-post behaviors of coal miners from two levels (coal miners and coal mine enterprise). Thus, equilibrium and dynamic evolutionary analyses of the two parties should be conducted. Results indicated that, in the enterprise’s perspective, inspection cost and punishment intensity are important factors that influence the safety production and economic benefit of coal mine enterprises; in the coal miners’ perspective, wage loss and the constraint degree it generates are essential factors. Furthermore, these factors constitute a key to solving off-post behaviors of coal miners. Reasonability of the established simulation model was analyzed and verified on the basis of off-post behaviors of workers from a coal mine that belongs to Yanzhou Coal Mining Co., Ltd. The coal mine enterprise should enhance the inspection of safety production and establish scientific and complete off-post punishment mechanism. Moreover, the coal mine enterprise should provide proper compensation, treatment, and reward policies of workers to reduce the off-post behaviors of workers from a coal mine enterprise effectively.

ACTIVITY BASED COSTING – A TOOL OF ACCURATE COSTING

Activity based costing is a system of allocating overheads to jobs, processes or products on the basis of activities responsible for such expenses, instead of the traditional system, so that true and logical cost is obtained. According to traditional system, firstly the overheads are apportioned over various departments on some basis and then they are absorbed to the individual product on the basis of direct wages or direct labour hours or direct machine hours etc. Suppose factory overheads are absorbed on the basis of machine hours, this is not logical, because all factory overheads are not dependent on machine hours and so the overheads allocated are incorrect and consequently the total cost and selling price based on such costs are all incorrect and illogical, which may put business into trouble. The overheads are absorbed under Activity Based Costing on the basis of activities giving rise to overheads, e.g. to allocate the expenses of procurement of goods, it can be divided into three activities like placing an order, receipts and inspection, storage etc. The total overheads of all three activities are ascertained and are absorbed to various jobs, processes or products in proportion to the services which they received from these activities, e.g. the inspection cost is absorbed on the basis of number of times the product is inspected, cost of placing an order is allocated on the basis of number of times the orders were placed etc.

Productivity Enhancement: Implementing and Analyzing Clustering Method in Manufacturing of Gearbox Housing

Productivity is the index of performance with which assets, each human and material, are converted into beneficial services and items. The vital relevance of the present work was to research the elements involved in the development of productiveness in all its types which include capital, material, labor, machine, and general productivity at the enterprise. This turned into received by means of reducing the manufacturing cost of the component through reduction of its cycle time and increasing the month-to-month production implementing clustering method. The experimentation found out that the usage of proposed methods and improved tooling has increased the monthly production rate by 20% by dint of reduced cycle time. Rejection rate, i.e., defected components has decreased up to 2%. A reduction of 9.7% in part manufacturing cost was recorded. Tooling cost has decreased by way of greater than 10%. Up to 50% saving in inspection cost was reported on account of closer dimensional tolerances and superior finish achieved on manufactured parts. An improvement of 5.25% was claimed in total productivity.

System for the recognition of wear patterns on microstructures of carbon steels using a multilayer perceptron

This paper describes the application of a recognition system wear patterns present in carbon steel, the system classifies the microstructure of the materials which have three conditions throughout life-time in thermoelectric plants. This approach employs the artificial neural network multilayer perceptron in conjunction with the digital image processing to recognize the different physical states of the materials used as conductors in conditions of high temperatures. The studied patterns in the microstructure are spheronization, decarburization and graphitization. The microstructure is revealed from microscope images obtained in the Testing Laboratory Equipment and Materials of the Federal Electricity Commission in Mexico (LAPEM-CFE). The proposed system compared to the human expert, obtained an accuracy of 96.83 % with a shorter analysis time and inspection cost.

Probabilistic optimization of fatigue maintenance for welded components in steel bridges based on LEFM and LCCM

In this paper a probabilistic-based method for fatigue maintenance optimization of steel bridge’s welded joints, combined with linear elastic fracture mechanics (LEFM), the structure reliability, and life cycle cost method(LCCM) is proposed. The probabilistic analysis method can be used with the fatigue maintenance of steel bridges. Weld cracks are classified by its size and maintenance decisions, and are made according to its size classification. Maintenance cost is divided into inspection, repair and failure costs, according to the life cycle cost method. The maintenance optimization strategy is transformed to minimize the expected lifetime total costs with the constraints of the minimum acceptable reliability index to attain the most cost-optimal inspection and repair for the balanced costs between risk and safety. An example concerning the transverse stiffeners of welded components in the main girder of suspension bridge is investigated through the research of some parameters sensitivity. Among all the parameters, the inspection cost is the most remarkable. The optimal time interval of repair will delay based on the increase of the inspection cost. The optimal time interval of repair will advance based on the increase of repair cost. A discount rate can drastically change the value of the total cost, but when the probability of failure is very small, the increase of failure cost has little effect on the optimal time interval of repair. The method presented in this paper can be conducted using the similar maintenance of steel structures.