SMV means Standard Minute Value.
Basic (Normal) Time = Observed Time * Rating Factor
= Observed Time * (Performance Rating / Standard Rating)
SAM = Basic Time + Allowance %
Observed time means average cycle time recorded by observer; if it is recorded in second then convert it to minute (by dividing 60)
Rating Factor is performance rating divided by standard rating (standard rating is always 100). Performance rating is the speed of qualified worker observed by experienced observer considering worker's work station, work concentration, tendency to work, motion sequence, motion repeating tendency and over all how much running his/her work in a definite way. Performance rating can be less or more than the standard rating i.e. over or less than 100.
If his/her work seems better than standard then it should be decreased the time and if his/her work seems not good than standard then it should be increased the time (see below example), because less time means better performance & more time means relatively bad performance than standard.
For SAM calculation add allowance % with the Basic time. Allowances can be Machine allowance, personal allowance, Fatigue allowance and may be some other considerable allowances as per the work criteria.
Example:
Suppose observed time is 35 second, multiply it with Rating Factor. suppose the work is running as standard (comparing by the experienced observer) then it can be rated by 100 i.e. performance rating is 100 and for getting rating factor it will be divided by standard rating; So, 100 / 100 = 1. Now here the rating factor is 1 that means the work is running as per standard performance and then not necessary to increase or decrease the performance. So now the Basic time = (35sec/60) min * (100/100) = 0.583min.
[ If the performance shows better than standard then performance can be rated as 85 for decreasing the time ( because less time means good performance) therefore Basic time = (35sec/60) min * (85/100) = 0.495 min and if the work shows relatively bad than standard then it can be rated as 110 for increasing the time. Bad performance means more time needed performance. Now for bad performer, basic time = (35sec/60) min * (110/100) = 0.641 min.]
Finally for SAM calculation, add allowance % with basic time, suppose total allowance is 14%.
Now, SAM = 0.583 + (0.583*14/100) min or 0.583*(1+14/100) min = 0.665 min
Thanks
Nazmul
