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Enige aspecten van de spreiding van arbeidsprestaties *
Author(s) -
Jong J. R.
Publication year - 1950
Publication title -
statistica neerlandica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 39
eISSN - 1467-9574
pISSN - 0039-0402
DOI - 10.1111/j.1467-9574.1950.tb00422.x
Subject(s) - variance (accounting) , standard deviation , mathematics , section (typography) , variation (astronomy) , statistics , distribution (mathematics) , factory (object oriented programming) , computer science , mathematical analysis , physics , economics , accounting , astrophysics , programming language , operating system
Summary Some aspects of the spread observed in time studies. In the introduction the importance of time studies in mass production is mentioned. Next figures 1, 2 and 3 give some examples of the frequency distributions observed for the time intervals required for cyclical factory operations. It is pointed out that for comparing different jobs the specific deviation, s/√t, is often more useful than the standard deviation, s, or the average time t̄. If greater detail is required a study of the historic sequency may be of advantage; this sometimes reveals marked periodicity in speed (fig. 5). If one cyclical operation is split up in a number of phases, the variance of the whole is often larger than the sum of the variances of th; components, wich demonstrates the existence of correlations. Sometimes the distribution of 1/t or of 1/t 2 is found to be slcser to normal than that oft. In ajinal section the main causes of variation are briefly surveyed.