【文章內(nèi)容簡介】 or estimates 26 Time Study Suitable Jobs ? Job performed by a single worker in a fixed location ? Job involves repetitive short cycles ? Job expected to continue unchanged for a long period ? Job produces large quantities of output ? Resulting time standard must be very accurate 27 Time Study ? Analysts use stopwatches to time the operation being performed by workers ? These observed times are then converted into labor standards ? The labor standards are expressed in minutes per unit of output for the operation 28 Determining Labor Standards from Time Studies Observed Time Normal Time Standard Time Performance Rating Allowance Fraction 29 Determining Labor Standards from Time Studies 1. Make sure correct methods are being used to perform the operation being studied. 2. Break the operation down into basic tasks (elements). 3. Determine how many cycles to time. A cycle is one plete set of the elemental tasks. 4. Observe and record the elapsed time for each element for the number of required cycles. . . . more 30 Determining Labor Standards from Time Studies 5. For each element, estimate the observed worker’s performance rating. A rating of indicates the worker is working at normal speed. 6. Compute the allowance fraction for the operation. The allowance fraction is the fraction of time that workers cannot work through no fault of their own. . . . more 31 Determining Labor Standards from Time Studies 7. Compute the mean observed time for each element: (Sum of observed element times) (Number of cycles timed) 8. Compute the element normal time for each element: = (Mean observed time) x (Performance rating) . . . more = 32 Determining Labor Standards from Time Studies 9. Compute the total normal time for the entire operation: = (Sum of element normal times for all elements) 10. Compute the labor standard for the operation: = (Total normal time) / (1 Allowance fraction) 33 Example: Time Study Approach In a time study of a manufacturing operation, the average time observed to plete a product was minutes. The performance rating applied to the observed worker was and the allowance during an 8hour shift was % or 60 minutes. Compute the labor standard. 34 Example: Time Study Approach ? Observed time = minutes ? Performance rating = ? Allowance fraction = ? Normal time = Observed time x Performance rating = x = minutes ? Standard Time = Normal time / (1 Allowance) = / (1 .125) = / () = minutes 35 Work Sampling ? The work of one or more employees is randomly sampled at periodic intervals ? Noted is the proportion of the total operation that is accounted for in one particular activity ? The results of these studies are used to: ? Set allowances used in labor standards ? Set labor standards 36 Work Sampling Suitable Jobs ? Job performed by a single worker in a fixed location ? Job involves repetitive short cycles ? Job expected to be changed periodically as customer orders change ? Job produces relatively small quantities of output ? Resulting time standard used for accounting cost standard, pricing analysis, and production planning 37 Example: Work Sampling A work sampling study was performed on an electronic assembly operation at OK Instruments. The study covered an 8hour shift with a single worker. The results of the study were: Activity % of Worker’s Time Assemble Units 80 Allowances 20 If the worker received a performance rating of