摘要:

A three parameter time constant learning curve model is applied to four case studies and the optimum parameters determined in the least sum of error-squared sense. The error residuals are then analysed using correlation, regression, and cusum techniques. A global range for learning curve scatter is derived from grouped data. One case study establishes a sinusoidal trend additional to wide-band noise. In all cases studied there is correlation between successive error residuals so that there are many less sign changes than predicted from an assumption of normally distributed, uncorrelated scatter. A simulation model is documented which generates artificial learning curves with the requisite degree of correlation as evident in terms of the number of sign changes. The results of the paper may be used to establish the a priori scatter estimates necessary in various parameter estimation techniques developed for on-line prediction of human operator future performance.

ISSN:0020-7543    

DOI:10.1080/00207547508942980

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Despite the numerous studies on human lifting ability no Berious attempt has been made to devise an empirical prediction model based on a large number of task factors rather than individual factors. This paper first demonstrates that the effect of one variable (age) is similar in a study of 45 subjects using a non-compact object to that found in previous studies using compact objects. A model is proposed to predict lifting performance from a large number of task-related variables. A test of the model using the effects of five variables estimated from the literature was conducted. Twenty-six lifting conditions were tested and the model predictions matched the actual weights lifted with a correlation coefficient of 0-936. The implications for future extension of the model are discussed.

ISSN:0020-7543    

DOI:10.1080/00207547508942981

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

In this article first a very brief overview is given of the main sociotechnical concepts and authors. This is followed by a rather critical examination of this approach, viz. from a methodological and a system theoretical standpoint. After that some suggestions are given for an improvement, in sociotechnical thinking, that might be fruitful with respect to the development of a theory.

ISSN:0020-7543    

DOI:10.1080/00207547508942982

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

This paper deals with an investigation undertaken for the purpose of determining the requirements of a measuring system capable of monitoring, on-line, the workpiece geometry on a cylindrical grinding machine. Results of a typical teat are presented under the categories of three components of geometrical error, i.e. out of roundness, waviness and surface roughness.

ISSN:0020-7543    

DOI:10.1080/00207547508942983

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

This paper presents some case studies of quality control practices based on the authors’ visits to some manufacturing industries. The statistical methods applied in each quality control programme are emphasized.

ISSN:0020-7543    

DOI:10.1080/00207547508942984

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

A critical assumption in balancing assembly lines is that the line is ‘ serial ’ with no ‘ paralleling’ of tasks allowed. This constrains the cycle time to be at least equal to the maximum task time, which in turn limits the production rate. One alternative to increasing the production rate (hence lowering the cycle time) is by allowing parallel tasks in the assembly line at the cost of additional facilities. In this case, the problem becomes one of selecting the tasks to be paralleled such that the total cost is minimized. This problem is formulated as a mixed integer programme, and a branch and bound algorithm is presented for its solution. The structural properties of this programming problem are discussed, which con be used to improve the computational efficiency of our branch and bound algorithm. An illustrative problem and preliminary computational results are provided.

ISSN:0020-7543    

DOI:10.1080/00207547508942985

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The flow-shop sequencing problem with no wait in process and with jobs requiring dissimilar technological order for machine processing is formulated in this paper. A systematic method is suggested for obtaining the optimum solution to the sequencing problem. An example of four jobs with four technological orderings for machine processing and four machines is solved to illustrate the suggested method.

ISSN:0020-7543    

DOI:10.1080/00207547508942986

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Analytical solutions for the mean cycle time of a two-stage series production system with variable operation times at the stages are presented. Although the methodology is applicable to any type of service time distribution at the stages, typical cases of Erlang and normal distributions are worked out in detail. It is shown that the problem of a multi-stage unpaced belt production system can, in principle, be reduced to one of integration, for arbitrary service time distributions at the stages. Detailed expressions are obtained for the mean cycle time and in process inventory of a two-stage series production system with provision for an arbitrary level of interstage inventory. The service time at one of the stages is assumed to be constant and the other distributed exponentially. The analysis leads to the conclusion that at high values of coefficient of variation, the type of service time distribution has a considerable effect on the overall throughput of the system and unbalancing has a favourable effect on the efficiency of a two-stage series system when the variability of service times at the stages is not the same.

ISSN:0020-7543    

DOI:10.1080/00207547508942987

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

ISSN:0020-7543    

DOI:10.1080/00207547508942989

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

ISSN:0020-7543    

DOI:10.1080/00207547508942991

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor