Abstract:
The Ultrasonic Cleaning process is an important process for Suspension
production. The demand forecasting of a customer indicates that demand of a
suspension model namely Cougar is increasing continuously. According to this
forecasting data, the capacity of the ultrasonic cleaning process will not be enough to
support the future demand. This research intends to make a study on the capacity
improvement in the cleaning process by reducing its cycle time. From the time study of
the process and analysis of multiple activity chart, the current cycle time of cleaning
process is equal to 566 seconds, while the cycle time that is required to meet the output
target is equal to 486 seconds. The experiment results shows that the cycle time can be
reduced to 120 seconds. Next, two alternatives to decrease the cycle time are proposed
including: 1) Reduce washing time to 120 seconds without rearranging the sequence of
the robots. and 2) Reduce washing time to 120 seconds and rearrange the sequence of
the robots. According to the simulation results, the lowest cycle time is given by the
alternative 1. By using alternative 1, this factory can increase the capacity of cleaning
process by reducing the cycle time to 391 seconds. However, when considering the
variability of the preceding process, we found that the capacity can only be increased to
1,093,602 pieces per week. This new capacity is not consistent with the target.
Therefore, we use Optquest function in Arena to find the appropriate cycle time of the
preceding process. The result of simulation also shows that the cycle time of preceding
process (6 production lines) should be 27 minutes/Lot (Poisson distribution), which
results in increasing the capacity of cleaning process up to 1,293,335 pieces per week.