Efficiency Methods
An Introduction to Scientific Management

112 EFFICIENCY METHODS Mr. Knoeppel in two articles on time-study1 states also that there can be no absolute rule as to a fair standard; but that halving the difference between best time and average time has given very good results. Mr. Emerson’s standard is 50 per cent, of his fastest worker’s achievement.-2 At the Watertown Government Arsenal an allowance as large as 66 j per cent, on best time was given. In the experiment quoted on p. 94, the best time being determined as 24 minutes, 40 minutes was made standard ; and most workers soon accomplished the work in less—one in 20 minutes, as related. It is noted that initially the workers, before they had tried, were extremely sceptical that the work could be done in 40 minutes. Mr. D. V. Merrick3 attacked the problem by the direct use of statistical methods, in which perhaps few will care to follow him. He computes the average time taken by each element in the operation, also the shortest time for each. Dividing the first by the second, he obtains the percentage deviation (the percentage that the minimum is below the average time). This number is obtained for every element in the operation, and the average is then 1 Southern Machinery, vol. xxxi. 2 Interview with Mr. R. G. Hoxie; see the latter’s book, " Scientific Management and Organized Labour,” p. 156. » Paper on Time Study read at the Efficiency Society Con- vention at Lake Placid Club, September, 1915. This is a very useful paper, and gives, among other valuable data, Mr. Barth's formula for the estimation of percentage for fatigue allowance, to which reference was made on p. 97.