Engineering Costs and Production Economics最新文献

In this paper an algorithm is suggested for determining the economic ordering policy for a product procured centrally by a supplier and distributed from a central warehouse to a number of retailers. The product is subsequently distributed to customers from the retailers. The objective is to minimize the total costs of the supplier resulting from the ordering costs, the distribution costs and the inventory carrying costs of the central warehouse and the retailers. An example is given to illustrate the method.

In recent years researchers have dealt with multiple time series problems in practically meaningful ways. In this paper, the assembly-line data of a major producer of automobile engines is analyzed and multivariate models are constructed and estimated to investigate the relationship among weekly engine production, downtime and the man-hours worked. The assembly line is operated on a Just-In-Time basis for normally two shifts per five day week. Such an analysis could help them in developing contingency plans consistent with their obligations to the automobile manufacturer they supplied.

In this paper a model which explicitly recognizes the relationships between the plant capacity, the lead time for building the plant, and the discount rate used in evaluating the project, is developed. It is shown that the introduction of a discount rate which is a function of capacity, substantially alters the results obtained in a previous study where the discount rate is assumed to be constant. In particular, since the net benefits of an additional unit of capacity is discounted using a higher rate, the NPV is suppressed. An extensive sensitivity analyses on the nonmonetary and monetary parameters and their effect of the optimal plant size vs optimal NPV is provided.

This paper deals with the graphic simulation package developed to simulate mobile robots working in warehousing environments. Paths are planned for each robot that takes care of constraints and possible chances of collision with other robots. Decision making and simulation in real time dynamic environments is studied. Obstacle detection in the paths of the robots could result in bypassing the obstacle or path blockage. The effect on the other robots due to such “dynamic obstacles” is also analyzed.

In this paper sufficient conditions for optimality for the single machine job scheduling problem with a linear combination of total flowtime and sum of squared lateness as the objective function are developed. Based on the sufficient conditions a lower bound for the objective function for a given schedule is derived. A branch-and-bound procedure incorporating the lower bound has also been developed. In addition, we also show how to fathom nodes in the branching tree using the a-priori precedence relationships among the jobs that can be determined using the sufficient conditions. Computational experiments for the branch-and-bound and its results are also presented.

By means of two case studies, regarding large-scale series production and small-scale series production, the reliability and the productivity of flexible manufacturing systems are tested in an industrial environment. Furthermore the operational behaviour of a flexible manufacturing system (FMS) as compared to stand-alone configurations is investigated.

Parenco produces high-quality newsprint for several well-known European daily newspapers. To maintain their proud reputation, they must maintain both quality and quantity of production.

They use the Brüel and Kjær Systematic Machine Condition Monitoring concept to monitor the vibration spectrum at 6000 measurement points on their paper machines and power plant. The system features early fault detection, powerful fault diagnosis, and trend analysis to predict the lead time to breakdown.

This paper describes the use of this Brüel and Kjær system at the Parenco paper mill.

When a company installs flexible manufacturing systems (FMS), the results can be truly startling; e.g. a substantial reduction in the number of machines, number of employees, floor space, inventory level, throughput and lead time and also higher quality products, greater flexibility to respond to the market needs etc. But when one comes to financial analysis through the traditional evaluation approach, the results are really disappointing. This is so because of the inability of traditional modes of financial analysis, like discounted cash flow, to incorporate most of the strategic benefits of FMS in its analysis. FMS investments are strategic investments and their full impact on the firm is not estimable in terms of cash flows. What is required in investment evaluation procedure to truly justify investments in FMS is the combination of both strategic and financial methods. The paper aims at evolving a new investment evaluation procedure which will integrate strategic planning with financial method.