Considerations on Multi-Service on Workstations

2012 ◽  
pp. 371-397
Author(s):  
I. C. Dima
Keyword(s):  
Mass Production ◽  
Machine Tools ◽  
Optimal Number ◽  
Working Time ◽  
General Distribution ◽  
Serial Production ◽  
Working Cycle ◽  
Technological Structure ◽  
Effective Use ◽  
Production Conditions

Polyservicing the workplaces takes into account the cycle of processing the benchmarks by machine tools and their features and implies a thorough analysis of the technical, organisational, and economic aspects. It is thus intended to efficiently use the machines and machine tools including the worker’s working time. Grouping the processing operations by machine tools will be done depending on the technological structure of each operation, given the use index of the machines, the effective use index of labour, the structure and duration of the operations necessary to make the product, the type of the machine tools used. Polyservicing the machine-tools is featured by a series of parameters: the duration of the working cycle of a machine, the duration of the polyservicing cycle, optimal number of machines that can be services, the coefficient to use the performer’s working time, etc. Combining the operations to be done on various machine tools is based on the types of technological processes and is done separately for manufacturing unique products, serial production, and mass production. Establishing the optimal production conditions for polyservicing can be done by using the theory of “waiting queues” and “Markov chain,” which is based on three elements, namely: input into the process, the servicing mechanism, and the type and way of servicing. Optimising the polyservice of machines can be done using the “Takacs and Runnenburg model,” which basically solves the issue of the general distribution of servicing times and the “method of the mechanisation coefficient,” which takes into account the influence of cost on the number of polyserviced machines.

scholarly journals DETERMINATION OF THE ELEMENTS OF PRODUCTION CYCLE TIME IN SERIAL PRODUCTION: THE SERBIAN CASE

2014 ◽  
Vol 38 (3) ◽  
pp. 289-304
Author(s):  
Dragan Ćoćkalo ◽  
Sanja Stanisavljev ◽  
Dejan Đorđević ◽  
Milivoj Klarin ◽  
Aleksandar Đ. Brkić
Keyword(s):  
Cycle Time ◽  
Mean Value ◽  
Working Time ◽  
Experimental Investigations ◽  
Time Range ◽  
Production Cycle ◽  
Distribution Law ◽  
Serial Production ◽  
Working Cycle

A model for the stochastic determination of the elements of production cycle time is proposed and experimentally verified in this survey. The originality of the model as reflected in the idea of using a work sampling model to monitor the production cycle is one of the most significant indicators of production effectiveness and efficiency, instead of applying classical methods. It has been experimentally proved that for a corresponding representative set the elements of working time range according to normal distribution law and that, dynamically viewed, it is possible to use mean value calculations to establish control limits on three standard deviations for the individual elements of working time and thus to master the process. Based on our experimental investigations, it has been proved that in the practice of small and medium-sized enterprises with serial production it is possible to design and apply a very simple but accurate enough stochastic model to determine the elements of working cycle time and in this way optimize the duration of production cycle time.

Using the Graphical-Analytical Principle to Use Multi-Serving in Operational Management

2012 ◽  
pp. 423-443
Author(s):  
I. C. Dima
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
Analytical Procedure ◽  
Optimal Number ◽  
Cycle Duration ◽  
Minimum Duration ◽  
Working Cycle ◽  
Operational Management ◽  
The Way

When organising the system of polyservicing the machines and equipment, the graphical-analytical procedure is successfully used, which basically emphasises those factors that condition the simultaneous service of several jobs, factors that can be production substitutable and production limitative factors. When the technological operations are identical, they have the same duration and structure, the organisation of polyservice is based on establishing the cyclogram for servicing all machine tools that have been taken into account. If the operations are different, but have the same manufacturing cycle duration, the use of polyservice implies the determination of the optimal number of machines that are to be simultaneously serviced and the preparation of the servicing cyclogram for all simultaneously serviced machines. Should the operations be multiple, but some of them have the same duration and the same cycle, each machine has a different cycle, but in between these cycles, there is a ratio established between the maximum and the minimum duration influencing the polyservice cycle and the number of machines to be possibly serviced. When the machine tools perform different operations, the way to achieve polyservicing is based on determining the polyservice working cycle, taking into account the longest working cycle of the machines and the amount of servicing times of every machine tool. When the machine tools are grouped, by duration of processing operations for various machines, polyservicing several machine-tools at the same, polyservicing cycle is achieved. Regardless of how polyservicing is done, a system of aggregate indicators whose level is calculated based on mathematical formulae is used in order to assess polyservicing.

scholarly journals Measuring the bore straightness during reaming with sensoric tools

2020 ◽  
Vol 14 (4) ◽  
pp. 535-544
Author(s):  
Andreas Bretz ◽  
Eberhard Abele ◽  
Matthias Weigold
Keyword(s):  
Mass Production ◽  
Cost Efficiency ◽  
Machine Tools ◽  
Processing Time ◽  
Process Chain ◽  
Machining Processes ◽  
High Quality ◽  
Random Samples ◽  
Hydraulic Valves ◽  
Productive Time

Abstract Reaming plays a crucial role in production to meet the high quality requirements of precision bore machining. It is either directly responsible for the final component quality or influences subsequent processes such as honing. The narrow tolerances are usually monitored by measuring random samples in mass production due to cost efficiency. Having a closer look at an exemplary process chain for the production of hydraulic valves shows the possibility to adapt the honing parameters which reduces processing time and costs. However, the bore straightness after the reaming process has to be known. In this paper an approach is presented which allows to record the bore straightness within the productive time. For this purpose, a sensory reaming system is developed. It can be used without additional components in the machine tool and thus integrated into existing machining processes. Cutting tests show that the system is able to measure the bore straightness as good as sensing probes used in machine tools.

scholarly journals Ultra-precision: enabling our future

2012 ◽  
Vol 370 (1973) ◽  
pp. 3993-4014 ◽  
Author(s):  
Paul Shore ◽  
Paul Morantz
Keyword(s):  
Mass Production ◽  
Machine Tools ◽  
Well Being ◽  
First Century ◽  
Precision Engineering ◽  
Precision Machine ◽  
Ultra Precision ◽  
Manufacturing Accuracy ◽  
Precision Machine Tools ◽  
Wealth Generation

This paper provides a perspective on the development of ultra-precision technologies: What drove their evolution and what do they now promise for the future as we face the consequences of consumption of the Earth’s finite resources? Improved application of measurement is introduced as a major enabler of mass production, and its resultant impact on wealth generation is considered. This paper identifies the ambitions of the defence, automotive and microelectronics sectors as important drivers of improved manufacturing accuracy capability and ever smaller feature creation. It then describes how science fields such as astronomy have presented significant precision engineering challenges, illustrating how these fields of science have achieved unprecedented levels of accuracy, sensitivity and sheer scale. Notwithstanding their importance to science understanding, many science-driven ultra-precision technologies became key enablers for wealth generation and other well-being issues. Specific ultra-precision machine tools important to major astronomy programmes are discussed, as well as the way in which subsequently evolved machine tools made at the beginning of the twenty-first century, now provide much wider benefits.

scholarly journals Methodology of technological and operational factors accounting in the process of complex optimal design of microand nanodevices manufactured using group technologies

2018 ◽  
Vol 224 ◽  
pp. 02094
Author(s):  
Sergey Meshkov
Keyword(s):  
Optimal Design ◽  
Group Technology ◽  
Design Stage ◽  
Time To Failure ◽  
Serial Production ◽  
Operation Conditions ◽  
Optimal Balance ◽  
Operational Factors ◽  
The Given ◽  
Production Conditions

The problem of providing key quality indicators (indicators of purpose, manufacturability, reliability) of micro-and nanodevices at the design stage is considered. The limitations imposed by a group technology production on methods ensuring serial production availability and reliability of micro- and nanodevices are described. The design of micro-and nanodevices methodology that allows to ensure the optimal balance between serial production availability in the given production conditions and time to failure in the specified operation conditions under given restrictions on the device purpose indicators by taking into account the technological and operational factors is described.

Machine Tool Service for Mass-Production Machining Systems

2018 ◽  
Vol 12 (4) ◽  
pp. 507-513
Author(s):  
Makoto Fujishima ◽  
◽  
Takashi Hoshi ◽  
Hiroki Nakahira ◽  
Masafumi Takahashi ◽  
...  
Keyword(s):  
Machine Tool ◽  
Production System ◽  
Mass Production ◽  
Machine Tools ◽  
Production Systems ◽  
Production Volume ◽  
Machining Processes ◽  
In Series ◽  
Tool Service ◽  
Large Production

Mass-production machining systems that are comprised of machine tools are often configured in series by dividing the machining processes in order to manage the large production volume. This indicates that if one of the machines stops owing to a mechanical malfunction, the entire production line needs to be stopped. Thus, machine tools in mass-production systems are required to be highly reliable and easy to maintain. Predictive maintenance, which enables operators to detect any signs of failure in the machine tool components, needs to be performed for the machines as well. In this work, various approaches for the improvement of the maintainability of machine tools used in a mass-production system are reported.

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