A freight car in the United States spends approximately two-thirds of its time stationary; a significant portion of this time in hump classification yards is spent in queues waiting to be inspected and classified into outbound trains. This paper describes the development of a model for these queues and the application of the Monte Carlo method to the analysis of these queues for a particular classification yard. An elementary form of feedback is included in the model. Using the model of yard operation, certain methods of improving yard operation are determined. Operations Research, ISSN 0030-364X, was published as Journal of the Operations Research Society of America from 1952 to 1955 under ISSN 0096-3984.

This paper is the case history of an operations-research study of a barge line undertaken in the summer of 1954. One problem considered was the scheduling of tugs and the determination of the resulting number of barge loads per year which would result. The second problem was to determine the proper balance between tugs and barges for three or four tugs. These problems were solved by simulating the operation, the results of the simulation led to recommendations and predictions. These predictions are compared to the actual data over the ensuing years as the recommendations were carried out.

É a contabilidade instrumento obsoleto de administração, ou linguagem adaptável às novas descobertas científicas que afetam o processo de decisões administrativas? 't. o cientista, seja êle o matemático, o físico ou o antropólogo, é um recém-chegado ao campo da decisão. :E.1esente, entretanto, grande confiança em sua capacidade de ajudar, tal

A survey of recent history of and techniques in transportation methods.

A description of the characteristics of decision tables—guidelines and examples—are offered to educational administrators as an efficient alternative to linear prose and flowchart formats. Described are three types of decision tables: limited entry, extended entry and mixed entry tables. Completeness checks and rule compression are also explained. Decision tables provide an excellent means of describing the relationship between antecedent conditions and innovative actions. When properly utilized, decision tables can bring clarity, accuracy and analysis to the decision making process.