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Work is discussed in which the service returns of automobile components, together with life mileage information are used to formulate relationships for forecasting future service requirements. Previous production levels of the components concerned are used, and regression analysis is applied to take into account the fact that any given manufacturer has only a proportion of the spares market. Comparisons with other forecasting techniques are given. [ABSTRACT FROM AUTHOR]

Presents an introduction of the initial publication of the "International Research Journal." Focus of the journal; Significance of the study of production to economists; Aspects of production to be discussed in future issues of the journal.

The major problem in the operation of a selective assembly plan is 'mismatching', where the number of components in one category does not match the numbers in the corresponding category of the mating component. This is generally because of the wide differences between the natural variability exhibited by the processes producing the parts. The Natural Process Tolerance is defined and its relationship to the tolerance specification established. Selective assembly problems are classified, the design and manufacturing procedures are developed and illustrated by case examples. A case history of a piston-cylinder fit is described, showing how a serious mismatching problem was approached. [ABSTRACT FROM AUTHOR]

Tests were run with high strength thermal-resistant work materials selected by surveying U.S. aircraft engineering companies to find representative types of materials presenting problems in conventional machining. Each material tested had two different heat treatment procedures. Tests were conducted in orthogonal and conventional turning, in milling and in drilling operations using different methods of workpiece heating. Information was obtained on tool life--cutting speed relationships, tool temperatures and forces, chip formation and related quantities for a range of work temperatures. Metallographic studies of hot-machined parts were carried out and the effects of the process on workpiece geometry are discussed. Assessment of workpiece heating methods will be the subject of a further paper. [ABSTRACT FROM AUTHOR]

Many situations occur in industrial systems, where decisions have to be made from time to time about the manner in which the system shall be operated. This paper concerns a class of situations in which, because of rising costs of operation per unit time, it is necessary to decide when to overhaul the system to minimize long run operating costs. The operating costs are assumed to be a quadratic function of operating time whose parameters are stochastic variables, which is the case with some electrolytic processes. The main purpose is to show how the Dynamic Programming approach can be usefully applied to such systems. [ABSTRACT FROM AUTHOR]

Two inventory control models are discussed, for continuous demand and for instantaneous demand. It is shown that minimizing the cost due to the uncertainty of demand is a special case of the criterion of profit maximization. Certain major assumptions, outlined in the conclusions, are used to define the situation but these may be modified to extend the applicability of the results. [ABSTRACT FROM AUTHOR]

The paper describes an electrical analogue for aiding the solution of the classical transportation problem. It is based on the Simplex method of solution due to Dantzig. Two simple basic circuits, a feasibility circuit and a cost comparison circuit, are provided for each source and destination pair. Switching enables the feasible routes to be selected and then explored for comparative costs. The procedure is iterative. By not being self-optimizing but aiming to eliminate the routine hand calculation a flexible machine is provided with simple components. [ABSTRACT FROM AUTHOR]

One of the problems which occupies the work study engineer is that of determining the number of observations necessary in order to estimate the work content of a job with a prescribed accuracy. A new equation is presented for this purpose. [ABSTRACT FROM AUTHOR]

This article presents an abstract of the paper A Study of the Variety of Paper Sizes in the U.K., by M. N. Pherwani and S. Eilon. Case studies in the consumption of stationery paper revealed a wide variety of products and a pricing policy which does not penalize customers for ordering non-standard or odd sizes. Cost analysis by use of break-even charts is not applicable, owing to the difficulty of allocating fixed costs to the various products. The amount of scrap caused by cutting paper rolls to predetermined stationery sizes is suggested as an alternative criterion, and application of linear programming to scheduling of paper sizes is demonstrated. An overall saving to the industry of about 2 percent of produced material is estimated to be the result if scientific scheduling is adopted.

This paper presents some general relations for the selection of speed, feed and depth of cut to achieve optimum economic conditions in machining. The relations are based on the assumptions that a power law relates the machining rate variables to tool life and to cutting power. Consideration is given to single point tools removing material in both one and two passes, and to operations involving more than one tool. Methods of establishing numerical data for practical application of the relations, are outlined briefly. [ABSTRACT FROM AUTHOR]

Among the techniques designed to reduce the subjective judgment, characteristic of conventional time study rating, are Dr. M. E. Mundel's objective rating and Professor Gerald Nadler's pace comparison. This paper describes a comparative study of these film-assisted techniques and conventional speed and effort rating, in which groups of graduate students and experienced industrial time study observers participated. Conventional speed and effort rating--still the most widely used rating technique--requires the observer to assess an operator's actual working pace relative to the observer's own mental concept of a standard performance of the work being studied. By contrast, objective rating and pace comparison necessitate, first, assessment only of the speed of the operator's motions, and that by comparison with the speed of motions demonstrated on a pace standard film. No attention is paid to job difficulty, and its effect on operator performance, until the second stage in the procedure when additional allowances of time are determined by reference to tables of secondary adjustments. Such adjustments were not examined in this present investigation. On the multi-image film loop used in this study, twelve paces of performing a simple job are shown simultaneously. The step film loop used consists of ten graduated working paces each preceded by an identification letter. In both films the relationship between the various filmed paces is known and related to one pace contained in each film representing the "standard pace" for the job. This present research is concerned with comparisons between conventional, multi-image and step film assisted techniques. [ABSTRACT FROM AUTHOR]

Random errors in inspection may lead to good products being rejected and defective products being accepted by inspectors. If the cost involved in rejecting good products is high, the supplier may be tempted to send back the rejects for re-inspection, in spite of additional costs involved in such a procedure (called "re-circulation" of rejects). This paper analyses several models to indicate under what conditions such a re-circulation policy is worthwhile. [ABSTRACT FROM AUTHOR]

After a review of ways of workpiece heating which have been used in previous researches, the authors discuss the basic requirements of a workpiece heating method. The development of a workpiece heating method using radio frequency resistance heating is then described. Tests were conducted with this method on a milling machine and a lathe. A variant of the method was later developed, "through the tool" radio frequency resistance heating. By using the tool as one of the electrodes, feeding the current in through the chip and removing it below the cutter by a sliding contact, very localised heating was obtained. Studies in heat flow and distribution were carried out to assist evaluation of the methods described. [ABSTRACT FROM AUTHOR]

A unique milling cutter dynamometer has been designed and developed which enables radial and tangential forces acting on a cutter tooth to be recorded throughout its cutting action. The research value of this instrument has been demonstrated in a series of comparative experiments involving up-cut and down-cut milling. This paper is based on original research reports of the design (Smith, 1958) and development (Ever, 1959) of a milling cutter dynamometer. Hitherto, the measurement of forces in peripheral milling has been mainly by dynamometer mounted on the machine table, though a few have analysed the torque and vertical force on the arbor. In such cases, standard cutters are used and the total vertical, horizontal or axial force is obtained. This present dynamometer has been designed to make possible direct measurement of the radial and tangential forces acting on a cutter tooth, throughout the formation of a single chip. A diagram of the dynamometer is given in Figure 1. The cutting tooth is carried in a block (1), the opposite end of which slides in the main body. Tangential movement of the cutter is restrained by straps (2) on either side of the body, and radial movement is restrained by strap (3) within the body. Strain, under load, of these straps is picked up by the perspex strain rings (4) and (5) each of which carries four resistance strain gauges forming a bridge unit. [ABSTRACT FROM AUTHOR]

This is an interim report on a comparative study of paced and unpaced worker performance. A number of pilot experiments are described involving simple physical and mental, including inspection, tasks paced by conveyor and other systems. Tentative findings are given, relating to output, quality of performance, distributions of operation times and ratios of constituent motion element times. Reference is made to preliminary work on computer simulation of paced systems. This Paper describes recent and current research at Birmingham which aims at contributing to the understanding and hence to the solving of these problems by way of comparative studies of the characteristics of paced and unpaced performance of workers engaged on highly repetitive tasks. [ABSTRACT FROM AUTHOR]

Selective assembly is used whenever the tolerances which have to be allowed for the components are so large that the natural build up with random assembly will not satisfy functional requirements. The traditional method divides the more variable components into a number of zones of equal width and then specifies what combinations of grades may be assembled so as to produce sufficient uniformity in the final product. Theoretically there is no limit to the number of grades which can be used, but there is a serious organisational problem of having only the specified categories available at one time, and another control problem to ensure that components are correctly graded. Further, a large proportion of components may not be usable through mismatching of quantities and this can increase costs considerably. These difficulties can be reduced by suitable quality control schemes which are additional to the grading operation. The method proposed in this paper is that components should be balanced by quantities rather than by size. It depends upon knowledge of all process capabilities and requires a quality control scheme to ensure that the mean size produced for every component coincides with the objective mean. The grading operation itself gives rise to a simple quality control scheme which is based on the balancing quantities. The same scheme is applicable to all components. Mismatching is impossible as long as control is maintained and all components are used in a reasonable period of time. It is shown that many applications can be made with only three grades and that even extreme sized components can be used. Methods are given to compute the variation which will be obtained from product to product when selective assembly is only applied to some types of component and the remainder are assembled at random. Thus, it is possible to design a procedure which will give sufficient uniformity at minimum cost and avoid the complexity of excessive numbers of categories. Err... [ABSTRACT FROM AUTHOR]

An approach to determining an acceptable equipment replacement policy is proposed for the case where the operating cost, as a function of age of equipment and purchase date, is fully known. The complete model representing optimum behaviour over an infinite horizon is presented. Because of the computational difficulties involved in the analysis of this model, a sub-optimisation method is suggested, which replaces the infinite stage problem by a single stage problem, modifying the operating cost function to include a "technological opportunity cost". A comparison of the consequences of this sub-optimisation in relation to the infinite stage model is presented for the purpose of ascertaining when the approximation suggested is valid. [ABSTRACT FROM AUTHOR]

Difficulties in defining fatigue have been recognized for many years; nevertheless, attempts are continually being made to give allowances for this nebulous phenomenon. Instead, attention should be directed towards the extent of the period of optimum performance, which is called the actile period. An operational description of the actile period is given. It is suggested that in light repetitive work the end of the actile period will be shown by an increase in variability -- supporting evidence on self-paced, semi-paced and rigid-paced tasks is given. Organization of work so that a "pause" occurs at the end of the actile period will produce optimum performance. The nature of a "pause" is discussed. There will be an actile period also for non-repetitive work, although the nature of the indication of the end of the period in relation to specific jobs has still to be determined. [ABSTRACT FROM AUTHOR]

This is a second progress report on a long-term research project on precision grinding. The relationship between specific energy and rate of metal removal--reported previously--is confirmed, and the study is extended lo examine the effect of wheel hardness. As a result there is some modification to the interpretation of this relationship. The pattern of wheel wear is related to the corresponding pattern of grinding forces. Surface finish throughout the run is shown to be dependent upon wheel truing and depth of cut, and to deteriorate as the run progresses following wheel truing to spark out. [ABSTRACT FROM AUTHOR]

An experimental technique had been developed for studying cutting with single tools of known geometry at very small depths of cut. It has been shown that the specific cutting energy decreases as the thickness of the cut is decreased, a result which is contrary to that obtained in previous investigations with grinding wheels and to that expected from consideration of the influence of specimen size on the yield value of shear stress. These apparent anomalies are discussed in terms of the width of cut and the size of the plastic zone. [ABSTRACT FROM AUTHOR]

Studies of the effectiveness of management control have usually been based on observations of inter-personal or inter-departmental relationships within an organisation. This paper suggests that a new approach would be to observe what happens to plans, decisions and tasks, from inception to completion. It discusses the application of scientific methods for analysing management control, with particular emphasis on research techniques for measuring and evaluating the effectiveness of control procedures. [ABSTRACT FROM AUTHOR]

This paper is a progress report on a study of an actual decision-making system. It scrutinizes the demands made on a manufacturing organization and the responses of the organization to these demands.
The study focuses on the ways the organization got a particular job done, namely the job of production scheduling and work-flow smoothing in the box-making plants of a manufacturer of shipping containers. The complete system can be factored into two parts. One sub-system places orders in sequence and prepares an advance production schedule. The second sub-system controls the flow of work through the actual manufacturing operations, making final adjustments in the sequence and speed of the work-flow. [ABSTRACT FROM AUTHOR]

Copyright of International Journal of Production Research is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of International Journal of Production Research is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of International Journal of Production Research is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of International Journal of Production Research is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of International Journal of Production Research is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of International Journal of Production Research is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of International Journal of Production Research is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of International Journal of Production Research is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of International Journal of Production Research is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of International Journal of Production Research is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of International Journal of Production Research is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of International Journal of Production Research is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of International Journal of Production Research is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of International Journal of Production Research is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of International Journal of Production Research is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of International Journal of Production Research is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In recent experiments on blanking and piercing it was found that cracks occurred in the region of maximum hardness gradient and that cracking could be eliminated by reducing the punch and die edges. In this paper a simple stress analysis is made of the corresponding plane strain deformation, account being taken of the strain-hardening property of the work material. The above experimental observations are then shown to be compatible with the predicted stress distributions. [ABSTRACT FROM AUTHOR]

The difficulties encountered when using a stop-watch for the measurement of basic time are well known and the authors of this paper suggest a new and more efficient method for such measurement without a stop-watch. A portable apparatus (consisting of a transistorized signal generator with a mechanical clock driven, hand wound, recorder) has been designed and is described. The authors wish at this stage to give interested persons the opportunity to comment upon the principle involved and hope that similar or alternative types of instruments will be constructed, utilizing the principle, and then subjected to practical testing in real work situations. The authors have communicated the results of a first test in this paper but the task of comparing the instrument with standard methods of time study has still to be carried out. [ABSTRACT FROM AUTHOR]

This paper discusses the application of Analogue Computers to the subject of Production Control and allied topics. A review is made of research applications of Analogue Computers to Economics, Operational Research and Production Control. The role of the Analogue Computer as applied to Production Control problems in British industry is also discussed. The probable course of future research and applications of analogue computation methods to problems occurring in Production Control is considered; a method of approach is proposed and an Analogue Inventory Policy Simulator described. [ABSTRACT FROM AUTHOR]

The article investigates the origin of self-induced vibrations in metal cutting. Self-induced vibrations which often occur in the cutting operation arc thought by some authors to result from the frictional sliding of the chip past the tool. Others consider that the vibrations are caused by a variety of factors such as the instability of the built-up edge or the intermittent cracking of the workpiece material ahead of the cutting edge. When brittle materials are machined, a characteristic squeal may often be heard; with ductile materials a squeal is never heard. This seems to suggest that the frequency of self-induced vibrations is related in some way to the brittleness of the workpiece material. If these vibrations result from the conditions at the chiptool interface, it is natural to look tor an explanation in terms of the impact characteristics of the tiny welded junctions which are thought to lock the micro-asperities of two contacting surfaces. In order to test this hypothesis, twelve different materials were turned under identical cutting conditions and vibration frequencies were measured. In an attempt to discover whether these tool vibrations leave cracks beneath the workpiece surface, a section of a brass surface which was machined under conditions of severe vibration was polished and etched. El'yasburg has proposed an explanation of self-induced vibrations in the cutting process, in terms of an intermittent cracking of the workpiece material observed just ahead of the cutting edge. Whether self-induced vibrations have their origin in the stick-slip motion of the chip past the tool, or the intermittent cracking ahead of the cutting edge, has yet to be determined.

A number of operational situations exist in which certain facilities are available and where a number of commodities must be processed on some or all of these facilities. The paper describes an algorithm to generate schedules which are near optimal or optimal with respect to the total processing time of all the commodities, the idle time of facilities and production rate. Thus, these schedules are characterized by near minimal or minimal total processing time and idle time of facilities and near maximal or maximal production rate. Usually this algorithm does not result in the desired schedule after the first application; it is therefore proposed to generate a set "D" of schedules from which the desired schedule can be selected. A decision rule determines the optimal number of elements belonging to set D. In order to justify the concept of the algorithm for the determination of the schedules mentioned above, an analysis is given of the decision tree associated with the sequencing model in terms of the probabilities related to the nodes in the decision tree. [ABSTRACT FROM AUTHOR]

This article presents researches published in the March issue of the journal "International Journal of Production Research." Technological developments, particularly in the metal and plastics fields, are causing rapid changes in industrial methods and are the subject of research in many parts of the world. Although these are extensive research areas, the Board welcomes papers relating to any branch of technology, since the production research worker must be aware of trends in manufacturing techniques. According to the article, researches into organizational or human aspects of production are being conducted in only a few countries, at present, but there is evidence of a growing interest in these research areas in the technologically advanced nations. The work being done in these fields of study can, at the moment, only claim to be exploring small parts of them, and it is probable that any researcher undertaking studies would produce results of considerable interest. The editors would, therefore, urge research workers to submit their reports for wide dissemination and comment by others in the international context of this Journal.

A group of Faculty members of the School of Industrial Management at Purdue University have for some time been engaged in studies of decision making in a large, decentralized American manufacturing company. These studies have investigated decisions at the mills producing raw material and the converting plants of this fully integrated company. Examinations have been made of decision processes within and between company plants with the objective of adding to theory of behavior in organizations, particularly theory of working relations and theory of cognitive processes in the carrying out of complex organizational tasks, and application of theory to the solution of practical problems, such as those of scheduling production and of formal organization.
This paper discusses one of these projects, an attempt to construct a behavioral model of the decision rules actually employed to schedule orders for production in one of the firm's plants. This project has sought to embody decision rules in a computer program which will, in fact, take incoming data on orders and plant capacity and convert this into an operating schedule in a manner highly analogous to that of the human schedulers who performed this task.[] The following discussion avoids technical details, since the aim of this paper is to give an overall picture of the major purpose and problems of this type of research; to describe its origin and to suggest possible future application as seen by the researchers. [ABSTRACT FROM AUTHOR]

In the manufacture of metal cans tinplate is a major cost item and when the scale of output of cans, say, in the food industry, is considered, it is obvious that efficient utilization of material is a factor of considerable economic importance.
The first part of this paper analyses in some detail the parameters which determine the optimal H/D ratio when trim losses are taken into account and makes a comparison with actual can dimensions used in the food industry. Having stated the optimal dimensions for an individual can, this study first attempts to estimate the sensitivity of these optimal conditions, that is to say what material wastage is expected to occur if deviations from optimal dimensions are considered. Secondly it was felt that the optimal solutions should be subjected to consumer tests so that some indication might be given as to customers' preferences, and to whether these are compatible with the theoretical optimal dimensions. Thirdly a solution is suggested for a multi-can programme in which a series of cans have a common diameter, and the implications of such a system on material utilization are discussed.
For a cylindrical can it can be shown by simple calculus that optimal use of tin plate is achieved when the height of the can is equal to its diameter. This, however, ignores trim losses in punching out end caps from a metal strip, which if accounted for may effect the H/D ratio quite appreciably. [ABSTRACT FROM AUTHOR]

Using circular arcs of tangential velocity discontinuity an attempt is made to account for some of the experimentally observed facts of rolling and rolling contact as between a circular "workpiece" and one or more parallel rolls. The same methods are demonstrated to apply to certain rotary forming operations.
The physical situations discussed in the first part of this paper arose out of a need to account for the phenomena of rolling contact; such contributions as have so far been made have thrown light on the problems of wear and on ball-and-roller bearing life. The last part of the paper will be seen to have obvious relevance to the Mannesmann and similar tube-making processes.
This essay endeavors to comprehend, though only to a modest degree, these different situations using a concept well known in the theory of plasticity, the tangential velocity discontinuity. The approach offered is speculative since the "solutions" proposed are based on over-simplifications which ultimately may not be adequately justified. However, because colleagues who originally read this essay in note form seemed to find it "plausible, interesting and suggestive", it was thought worthwhile to offer it for publication and discussion. The matter treated should at least bring attention to a very challenging area of mechanics which as yet claims an insignificant number of research workers. [ABSTRACT FROM AUTHOR]

Apart from the conventional theory of the minimum-cost or maximum-production cutting speed, a new concept of the machining conditions for maximizing the profit for the manufacturing enterprise was presented. Based upon this concept, a n analysis of the maximum-profit cutting speed was made and the theoretical expression for it was deduced.
The first step for economical machining is to select the most suitable type of machine tool for the production purpose. The next problem is to discuss the economics of machining itself, and high-production and low-cost tooling should be considered. Regarding the optimal machining conditions, Gilbert and other investigators analyzed the minimum-cost cutting speed at which the production cost per piece of products is minimum and the maximum-production cutting speed at which the rate of production is maximum.
In this paper, apart from the above concepts, the authors present a new concept of the maximum-profit machining conditions at which the profit for a manufacturing enterprise becomes maximum. Based upon this concept, the economics of machining was analyzed and developed. The expression for the maximum-profit cutting speed was deduced theoretically. [ABSTRACT FROM AUTHOR]

This paper describes briefly the context in which a portable system for recording certain aspects of drilling performance is being developed. Particular emphasis is placed on a time recording channel in which a sensing element attached to the quill of the machine conveys signals from the translatory feed motion to a sequential-event timer and recorder (SETAR--after the design of N. T. Welford).
Some discussion is devoted to indicating how the reliability of such a system is largely dependent on the method of collecting, transmitting and recording for subsequent analysis the excitation signals. [ABSTRACT FROM AUTHOR]

This paper examines the nature of the cyclic interference which may occur when two machines doing unrelated jobs are serviced by one operator.
A mathematical model is developed to cover the general case and this leads to a step-by-step procedure for interference calculation which may be computerized. The model facilitates analysis of the range and variability of interference so that rules for the economic grouping of future jobs may be developed. [ABSTRACT FROM AUTHOR]