Engineering Costs and Production Economics最新文献

Location decisions have a significant impact on the efficiency and success of an institution. Where an organization is located affects not only its ability to compete effectively but also itstransportation costs, labor costs, employee morale, public relations, etc. Location decisions are based on multiple criteria at least some of which are intangible, even emotional. This study proposes the Analytic Delphi Method (ADM), which permits the incorporation of intangible as well as tangible factors into the decision making process. The study illustrates ADM's application to location planning. ADM's strength lies in its integration of two strong methodologies: the Delphi method (a widely used forecasting and planning tool) and the Analytic Hierarchy Process (a mathematical model for multicriteria decision making).

This paper reports on an investigation which examined the effect of calculations made in fixed and current prices on the total productivity and partial productivities of a company manufacturing hardware fittings. The Craig and Harris productivity measurement model was used, and the calculations were based on 14 data sets collected on an annual basis over a reference period from 1971 to 1984. The collection of input and output data for use in the various models to measure productivity at the company level is not an easy task, it is made more difficult when deflator factors are employed and this may be one of the reasons for the opposition which some company managements appear to have to productivity measurement. The results from this piece of work indicate that total productivity and the partial productivities of capital, labour, material and miscellaneous are similar when calculated using fixed prices and current prices.

The conventional approach to the common cycle problem assumes a single production stage and takes into account only the setup costs and the carrying costs of finished inventories. This approach is limited to a single stage production process because the carrying costs of in-process inventories which are inherent in any multistage production process are not included.

This paper presents a multiproduct, multistage common cycle model. It differs from the conventional common cycle model in that it includes hidden in-process inventory carrying costs. The optimal common cycle is determined to minimize the setup, in-process and finished inventories carrying costs for a predetermined production sequence. A numerical example is then presented to compare the cost savings in using the revised model with the use of the conventional model.

The revised model provides insights of in-process inventory measurement and improves the current management thought and practice in common cycle decision making for a multistage production process. The ideas and findings of this paper are of managerial significance. The users of the revised model will be able to correctly calculate the optimal common cycle which results in cost savings due to greatly reduced lot sizes. The smaller lot sizes affect investment in inventories, production lead times, product quality and many other related operations management issues.

This paper considers the problem of the matching of the sales plans and the production schedules of a large Finnish, consumer-electronics producing, enterprise. A model, which was developed for use on a microcomputer and which processes both the sales plan and the production schedule simultaneously, is presented.

This paper presents a case study of production/inventory management in a mylar capacitor manufacturer. After a detailed analysis of the production/inventory system, the key decision variables along with the major environmental factors and their inter-relationships are identified. A computer simulation model of the system is then developed and simulation runs are carried out on a micro-computer to help determine the most appropriate setting of the decision variables subject to the stochastic effect of the environmental factors. This study illustrates the potential of combining simulation techniques with low cost computing facilities to create a powerful tool for effective management decision making.

The serial assembly model is considered. The problem is formulated to find sets of cost inputs for which solutions found by a recursion procedure remain valid. For simplicity a solution of this problem is provided for the two-stage problem. The paper shows that the stability region of cost inputs forms a convex cone in R⁴ and consists of a system of linear inequalities. An algorithm is provided to compute the parameters of this cone and several cases of changing only two parameters are displayed graphically.

In this paper we consider the policy of splitting each replenishment order among two or more vendors. This action reduces the expected time until the first replenishment arrives, as well as its variance. Thus using the same safety stock, a higher service level can be achieved or the safety stock can be reduced without decreasing the service level. We calculate these achievements using the expected shortage level as the service measure.

This paper examines the industrialisation policies adopted by developing countries and assesses its impact on inventory management. Factors influencing inventory demand are identified and the interaction between production planning and control and inventory control is considered as a key parameter. A reversal of inventory management objectives in a developing country environment is brought to light where the efficiency objective is given more significance than the cost objective.

This paper modifies the single end item production lot sizing model with the explicit incorporation of the effects of conversion of input to output at finite rates and the resulting work-in-process inventories, for both single stage and multistage production/inventory systems, under deterministic conditions. We show that the single stage model is a special case of the more general multistage model and illustrate our results through simple numerical examples.