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Replacement strategies applicable to items which fail with monotonically increasing failure rate are considered. In particular, the important characteristics of n-stage and 1-stage strategies are compared. This study, though somewhat tutorial in nature, reveals interesting properties which are useful in selecting an appropriate strategy. In general, n-stage strategy has economic advantage over the corresponding 1-stage strategy. The advantage is obtained by transferring failures from stages where failure costs are high to stages where these costs are low. In many cases, a quick examination of the system will reveal whether n-stage strategy will be advantageous or not. Subsequently, based on a detailed study an appropriate n-stage strategy can be designed. The more stages the greater would be the economy, up to where practical considerations and increasing transfer costs will limit the number of stages.

In this paper, an algorithm is presented which greatly facilitates the synthesis of optimal manufacturing systems by means of digital computation. The algorithm is based upon the use of the set-theoretic methods previously developed by Sewell and Porter (1971 a, b).

A model for multi-input manufacturing systems with in-process buffers is introduced based upon the concepts of system and subsystem reliability. A set of parameters is proposed for evaluating the effectiveness of individual buffers in relation to the total system. Through the technique of computer simulation an economic analysis of the use of buffers can be conducted by considering the reliability of facilities, downtime characteristic, work volume, labor cost, buffer cost, and buffer size limitations. The application of the model was demonstrated through an analysis conducted on an existing automotive Hood Assembly Line. The economic advantage and buffer size requirements as predicted by the manufacturing model are supported by the experience of plant management.

The industrial robot when associated with a workpiece magazine or conveyor system loading and unloading one or more numerical controlled machine tools opens a new way for automation in low series production. The possibilities for automatic handling together with machine tools within direct numerical controlled systems are discussed. After dealing with the master control selection and the signal flow some limitations resulting from the robot's kinematics are pointed out. Afterwards an actual manufacturing system, installed at the Berlin University, is introduced.

A sot-theoretic method of identifying constraints on the solution of system selection problems is applied to specific cases allied to the general problem in which the systems are resources used in manufacturing processes.

La práctica alfarera mapuche se caracteriza por su alto dinamismo, un fenómeno que ha caracterizado los sistemas de fabricación en la zona desde el siglo XIX. Siguiendo las propuestas de Pierre Lemonnier sobre la representación tecnológica de las estructuras que interactúan en los sistemas técnicos, se analiza el dinamismo documentado en las prácticas técnicas alfareras en tres niveles: la escala interna, como transversalidad tecnológica y en su vinculación con las dinámicas sociales. Como conclusión se plantea que este dinamismo está reflejado de múltiples formas y en diferentes ámbitos, siendo una característica intrínseca del propio grupo que, por ello, afecta a todas las esferas de la sociedad.

A classification of engineering systems is proposed in terms of the interplay between man-made structures and the natural environment. The functional classification distinguishes: (a) productive systems, divided in turn into extractive and manufacturing systems, and (b) service systems, which fall into active and passive systems. Active service systems are the most significant in the man-nature interplay because they are designed to produce certain desired changes in the environment or to prevent undesirable impacts by the productive engineering systems. Extractive and service systems, on the one hand, and the natural features affected by them, on the other hand, constitute integrated geo-engineering complexes that need to be studied, designed and planned as entities by interdisciplinary teams. Failure to fit past geo-engineering complexes properly into their physical and economic environment now requires costly remedial measures.

The contributions which human factors studies can make to industry are discussed in this paper. Broadly, contributions can be made in two areas, product design and the design and use of manufacturing equipment. The latter area is the major concern of this paper and some of the work done on ordinary manufacturing equipment is described. A major problem is the validation of human factors recommendations and it is pointed out here that the normal short-term evaluation is inadequate. For the effective use of people in industry it is necessary for human factors personnel to take a wider view of their contributions than has been common in the past and to consider their role in relation to the long-term operation of the whole plant.

In this paper the problems of introducing the teaching of a specialized subject into undergraduate courses are discussed with particular reference to the specific features of machine-tool technology. These cover the facts that the machine must be considered as part of an overall manufacturing system, so that the concept of performance differs from that encountered in other types of machinery such as internal-combustion engines, and that technological, economic, and human aspects must also be considered. Comparisons are made between Continental, particularly German, practice and present practice in some British universities. Some typical approaches to the organization of postgraduate full-time courses and short-term specialized courses are given. Finally, a comparison is made between the employment of university trained engineers in the machine-tool manufacturing and using industries in Great Britain and in Germany.

In this paper it is shown that the formalisms of set theory and sentential calculus can be combined to provide a powerful tool for the precise specification of the domains of capability of manufacturing systems. Such a specification is, of course, a pre-requisite for the solution of problems involving the optimal selection of manufacturing resources.

Industrial manufacturing experiments of formalin by use of a reaction tube having diameter 680mm with a standard capacity of formalin 10t/day (37% HCHO containing 10% CH3OH) have been carried out. An initial reaction was started by heating with a small electric heater (3kw) in the reaction vessel, heating for 2 hours was sufficient for reaction starting of the whole catalyst when the catalsyt was activated sufficiently, and it was confirmed that this method has enough merit for practical application in starting the reaction of industrial scale. The state of reaction was very good, that is, in the manufacturing formalin 10t/day, the reaction rate was around 60% at the theoretical yield of 95% and in the raction rate of 70-75%, the theoretical yield of 93-94% was obtained. The maximum production of 22t/day was obtained with the reaction rate of 69% and the theoretical yield of 93%, The spray-cooling effect, a characteristic of this manufacturing method, has been investigated. The theoretical yield and the space time yield were increased, and the space time yield was increased 8 folds under the same theoretical yield. This manufacturing system using the spray-cooling method is a new formalin manufacturing method of using of reaction tube having large diameter, it is entirely different from that of I. G. method and its value for practical application is confirmed.

This paper presents a combinatorial method of grouping objects into guest families, and of providing accommodation in a system of host cells. The method maximises the amount of hospitality extended...

In this paper, a method for the binary labelling of the elemental domains of capability of manufacturing systems is described and an associated calculus for the determination of the constraints which relate to the optimal selection of manufacturing systems is presented.

This paper describes the philosophy leading to the design and development of a numerically controlled turning machine, the Batchmatic 50, aimed specifically at the small batch production market. The machine has a maximum capacity of 2 in diameter bar, with a maximum turning length of 8 in. Particular attention is given in the paper to the reasons and thinking behind the design, and emphasis is given to consideration at the design stage of pre-set tooling and simple programming. The machine is seen as part of a manufacturing system, in which planning and organization play a vital part.

A brief review of available manufacturing systems is followed by an analysis of the problems faced by a company in the manufacture of components. The various manufacturing systems are then examined to see how well they solve the problems listed. It is deduced that a Group Technology approach provides the most efficient solution for the multi-component batch production factory and a discussion of the Group Technology approach is given.

Group technology, a manufacturing concept for small and medium quantity production, is receiving more and more interest from the machine-building industry all over the world. A prerequisite for the implementation is the grouping of parts, which are similar with respect to manufacturing. As an aid to this a classification system based on a form description is introduced. For the machining of this similar parts several manufacturing concepts according to the complexity of the parts have been developed, e.g. machining centres, flow lines and automats. Two case studios are presented. One is the layout of an unlinked flow line, the other one is the utilization of a machining centre. With the introduction of group technology in a firm, the design and work-planning departments can take advantage. Some hints are given with respect to that possibility.

In this paper the formalism of set theory is used to determine the constraints which bear upon the synthesis of optimal manufacturing systems to perform given work loads.

The machining centre concept represents a system of manufacture based upon the philosophy of performing complex cycles of operations at a single station. In carrying out cyclical combinations of tool changing, positioning and machining, it is evident that these basic operations interact not only with each other, but also with characteristics inherent in the products.

From the literary references and practice, there are a number of well known manufacturing processes to which different manufacturing systems can be allocated. Depending on the order batch size (small or large batches), functional machine layout and flow line systems (Fig. 2.1) are already recognized in the industrial manufacturing process.

Of all the potential advantages offered by group technology (G.T.), a reduction in throughput time and a corresponding fall in work in progress are the most frequently quoted. It is commonly held that further savings of investments in stocks and improvement in response from the manufacturing system can be achieved by a decrease in batch quantities, made economic by the setting-time reductions achieved by G.T.

This paper concerns manufacturing systems, which consist of one or several machining stations, integrated by workpiece storage areas, workpiece handling systems, and control systems. Corresponding to the hierarchy, shown in Fig. 1, it deals primarily with manufacturing systems of grade 2, which are multi-station systems. In relation to different manufacturing tasks different structures of manufacturing systems are possible. For determining the optimal structure in the totality of all possible structures it will be necessary to evaluate the structures of manufacturing systems in respect to their performance, their costs, and their behaviour in comparison with changing manufacturing tasks.

Publisher Summary This chapter discusses excitatory transmitter substances. The acetylcholine metabolism of sympathetic ganglia has been studied ever since the cholinergic nature of transmission was recognized. When the preganglionic nerve to the superior cervical ganglion is severed, the choline-acetylase in the distal segment virtually disappears in a few days, while there is even a transitory increase in the segment proximal to the section. Hence, it seems that the Ach manufacturing system is produced in the nerve cell and travels thence along the axon to the site of manufacture of ACh in the nerve terminals. The rate of synthesis is maintained at a high level even though the total Depot-acetylcholine (ACh) is not appreciably depleted. The ACh metabolism at neuromuscular synapses is much more difficult to investigate because they form a minute part of a nervemuscle preparation. ACh has been shown to be an excitatory transmitter at very few invertebrate synapses—for example, at neuromuscular synapses in the longitudinal muscle of the leech and in the retractor muscles of the holothurians.

Small and medium lot sizes and their variation are characteristic wide areas of mechanical engineering. They derive from the rapid development of science and engineering for satisfying the increasing social needs. This process is reflected by the new and continued development of technology, aimed at the permanent new and continued development of technology, aimed at the permanent new and continued development of technical goods with new and improved capabilities.

Stock levels and stocking policy to meet manufacturing and customer service requirements often lead to large sums of money having to be invested in slow moving items and large quantities of work in progress, much of which is designed for one specific need. Rationalization and standardization reduce the manufacturing and stocking costs, provided they are carried out with due consideration of re-order cost and effect on customer service. Within a Group Technology manufacturing system at Ferodo Ltd. consideration has been given to rationalization of semi-finished products for the manufacture of brake linings. The rationalization has not only led to a reduction of basic manufacturing varieties but also provided the basis for a new stocking policy.

Manufacturing systems are very complicated, so it is very difficult to grasp the actual behaviour of the manufacturing processes in detail. Even if we obtain a new idea of the scheduling algorithm or the process layout, it takes a long time until the idea is put into practical use, because it is difficult to prove the actual validity of the idea.The simulation technique is valid to solve this bottleneck. However, the conventional simulators lack the ability to simultaneously simulate the material flows and the control systems' behaviour.In this papers, the authors analyze the functions of manufacturing system in the following factors:(a) equipment layout (b) control system, (c) material, (d) operation. According to the analysis, we present a new type simulator which is named “MAFLOS&rdquo.MAFLOS is characterized by the following features.(a) MAFLOS has seven kinds of unit-element to describe the equipment layout of the manufacturing system. The simulation model is therefore generated by combining these unit-element.(b) MAFLOS can simultaneously simulate the material flow and the control system behaviour.

A data communication manufacturing system has been developed aiming at both automating to the extreme, routine works of comparatively low value, and centralizing engineering functions, including data, know-how, production planning, optimizing data processing, etc. in an integrated manufacturing system, as a cooperative research work between the Mechanical Engineering Laboratory, Makino Milling Machine Co., Ltd. and Fujitsu Fanuc Ltd.

As the cost of machine tools and manufacturing systems escalates, the attainment of an acceptable level of utilization and hence output becomes crucial. The present work describes certain procedures for measuring and subsequently improving the utilization of machine tools. A case study of the improvement in utilization of an NC lathe is detailed and it is emphasized that all machine tool purchase decisions require a prediction of the output of the new plant. Finally, an analysis concerning batch sizes indicates that, in general, utilization, as defined in this work can be markedly improved by increasing the batch size.

A DNC system was developed for a manufacturing system comprising about 20 NC machines. The requirements put on this system as well as its design will be described and discussed, especially the signals being transmitted between the computer and the numerical control, the electrical characteristics of the transmission lines, the organization of the computer programs and the disc storage.

Simulation is being used to attain a better understanding of many complex situations. In this analysis, GPSS/360 was employed as a simulation language to investigate the effects of operating policy guidelines and decision rules in the manufacture of component parts used interchangeably in the final product form. The analysis is developed on hypothetical data and interchangeable part mixture based on an actual manufacturing systems. A number of criterion measures are considered, and four policy decision rules are investigated.