Tuesday, February 8, 2011
Objective: To determine the standard time of an operation.
Equipment: Product to be assembled, tools for the operation, stopwatch, time
study form and table of allowance.
Procedure: 1. Divide the job into elements.
2. Conduct the stop watch time study and record the results in the
form provided. Record also the observed ratings.
3. If using continuous stop watch method, calculate the elemental
4. Calculate the number of observations required to achieve 95%
confidence level and ± 5% allowance error.
Where N = the number of readings to be determinedn = the number of readings in taken in preliminary study
x = the reading
5. Calculate the average rating.
6. Calculate the normal time.
7. Determine the allowance. (Table 1)
8. Calculate the standard time.
Allowance is the extra time added to the normal time to make the time standard practical and attainable.
There are 3 types of allowances:
1. Allowance for personal time.
The time an employee is allowed for personal things such as going to the bathroom, getting a drink and other operator-controlled reason for not working.
2. Fatigue allowance
The time an employee is allowed for recuperation from fatigue.
3. Delay allowance
The time given for unavoidable delays that are beyond the operator’ s control such as waiting for instructions or material, machine breakdown and maintenance.
Table 1 shows the allowance for assembly operation suggested by ILO (International Labor Organisation)
Tuesday, January 25, 2011
Introduction: Rating is the numerical value or symbol used to denote a rate of working (BS 3138). Standard rating is the rating corresponding to the average rate at which qualified workers will naturally work, provided that they adhere to the specified method and that they are motivated to apply themselves to their work. If the standard rating is consistently maintained and the appropriate relaxation is taken, a qualified worker will achieve standard performance over the working day or shift. The British Standard rating uses a scale of 0 to no activity and 100 to standard rating.
Objective: To test ability to rate the performance of an operation.
Equipment: Jigs and pins, stopwatch, time study rater trainer form, table of ratings
1. Use the forms provided for this experiment.
2. Observe the task of assembling pins using two hands.
3. Measure using stopwatch the time taken to assemble all 30 pins for 10 cycles.
4. Fill up the forms and calculate the actual rating:
Actual rating = Standard time / Actual time
5. Calculate the difference between the actual rating and your rating:
Difference = Actual rating – Your rating
Difference = Your rating – Actual rating
6. Calculate the total rating score:
Difference of 5% or less gets 10 points
Difference of 6% to 10% gets 5 points
Difference of more than 10% gets 0 point
7. Plot the ratings in the graph provided.