Motion and Time Study: A Case Study on A Short-Time Hydrostatic Failure Pressure Testing Process of Rigid PVC Plain-End Pipes

Abstract

This research work is relevant to the application of motion and time study techniques with two key objectives of the study. The first is to determine standard time of the short-time hydrostatic failure pressure testing process of rigid PVC plain-end pipes which is a bottleneck on the production line in a case study factory. The second is to introduce a practical guideline for a new approach to working that are capable to shorten the cycle time of the testing process on the basis of ECRS four principles. The result of preliminary survey on the hydrostatic failure pressure testing process of the rigid PVC plain-end pipes indicated that operations of the testing process can be divided into 20 sub-tasks. To determine the standard time of the process, counting the timing of sub-tasks was carried out with 10 cycles each in order to use for calculating the optimal number of cycles by using the Maytag table at a 95% confidence level and accuracy of ±5%. The result showed that the optimal number of timing cycles for all of 20 sub-tasks are not greater than 10, thus, the number of timing cycle of all elements were sufficient to satisfy the confidence and accuracy level. The average selected time and time allowances for each sub-tasks were then calculated and adjusted to obtain the individual standard times. The results from using ECRS principle for rendering process improvement have proved very effective in the new work method that not only could reduce the number of sub-tasks from 20 before the improvement to 16 after the improvement done, but also shortens the standard time from 978.16 seconds/piece (excluding the time required for failure pressure test with the hydrostatic pressure machine) down to 687.25 seconds/piece or cut down 290.90 seconds/piece which is 30% of the previous standard time.