WORK SAMPLINGNEEDLE DOWNTIME FOR GC LAB

By: AKSHAY SINGH VISEN NITESH KUMAR PAL POOJA RAWAT PRACHI GUPTA PRATYUSHA MALHOTRA VAIBHAW VISHAL SINGH VIKAS SHARMA

WORK SAMPLING

• A method of finding the percentage occurrence of a certain activity by statistical sampling and random observations.

• Other names used for it are 'activity sampling', 'occurrence sampling', and 'ratio delay study.

TYPES OF WORK SAMPLING

• Activity and delay sampling• Performance sampling• Work measurement

Calculation of sample size

n = Sample size (to find): Number of observations required for the desired confidence level and margin of error. p = Percentage occurrence of the activity expressed as decimal s = Error (desired accuracy) in fraction Formula for determining sample size:Sp=2 √ [p (1-p)/n]

Required confidence level=90% (It is necessary to decide what level of confidence is desired in final work sampling. Here the probability is that 90% of times the random observations will represent the fact and 10% of the time it will not)

OUR STUDY

METHODOLOGY

• The sample size is calculated

Here :n = Sample size to find p = 80%s = 10%sp=2 √[p(1-p)/n]0.1*0.8=2√ [0.8(1-0.8)/n]n=100

METHODOLOGY

• The observations are taken in a time frame of 4 hours

• Chits are prepared for random numbers and then the chits are drawn and the time arranged in order

• Then the observer on the scheduled time (as on the chits drawn) takes observation for different workers on each observation and notes if the subject under observation is working or idle

• The observation charts are then prepared for every hour and the total working time and idle time is calculated.

OBSERVATION CHARTSTime Working/Idle10:10 I10:22 W10:49 I10:36 W10:16 W10:01 I10:43 I10:13 W10:27 I10:59 W10:03 I10:23 W10:39 W10:50 W10:41 I10:28 W10:25 I10:12 W10:58 I10:05 W10:33 I10:19 W10:29 W

10:20 I10:45 I

CHART 1

CHART 2Time Working/Idle11:05 I11:12 W11:30 I11:45 W11:52 I11:14 W11:22 W11:18 W11:02 I11:33 I11:47 I11:25 W11:09 W11:59 W11:37 I11:43 I11:23 W11:27 W11:36 I11:57 I11:53 W11:51 I11:10 W11:48 I11:50 W

CHART 3Time Working/idle01:56 I02:22 W01:39 I01:50 W02:03 I01:38 I01:45 I02:27 I01:32 W02:17 I02:13 W01:43 W01:59 I01:37 W02:23 I01:54 I02:07 I02:11 W01:41 I02:28 I01:34 W01:51 W02:15 I01:49 I02:09 W

CHART 4Time Working/idle04:30 I04:41 W04:56 W04:07 I04:59 I04:15 W04:22 W04:27 I04:19 W04:10 I04:51 W04:46 I04:37 W04:57 W04:11 I04:16 W04:34 W04:05 I04:24 W04:40 I04:43 I04:31 W04:52 W04:01 I04:20 W

TOTAL OBSERVATION

• Total working state=13+13+10+14=50• Total idle state=12+12+15+11=50• Percentage of Working time(NEEDLE DOWN

TIME)= 50%• Percentage of Idle time(NEEDLE UP TIME)=

50%

RESULT

• The results indicate that the operator was idle 50% or 120 minutes a day (240*0.50=120)

• The results indicate that the operator was working 50% or 120 minutes a day (240*0.50=120)

THANK YOU