1st ICAI 2020

International Conference on Automotive Industry 2020

Mladá Boleslav, Czech Republic

Adding of pre-process contact sorting adds 3 seconds per 1 piece, this means that for 105 pieces of relay, this is an increase of 315 seconds. If the alignment operation of the process is to be removed, the time for 105 pieces must be determined. This is calculated as an average time of three workers at the alignment operation in Table 3. Table 3: The alignment operation times by workers per 1 pc of relay. Alignment operation times 1 st Worker 62 seconds 2 nd Worker 120 seconds 3 rd Worker 67 seconds Total 249 seconds Source: Hozzová, 2017 Average time of alignment operation per 1 worker is 249/3 = 83 seconds and for 105 pcs it is: 105 pcs × 83 = 8,715 seconds. Then time for production of 105 pieces of relays without adjustment but with contact sorting will be: 32,445 – 8,715 + 315 = 24,045 seconds. Failure rate by skipping the alignment operation would result in a level of 50.47% relay error, it means approximately 53 relays from 105 pcs. Since adjustment for 1 pc of relays is 83 s, for 53 defective pieces it is 4,399 seconds. In addition, RTG re-testing process would have to be included, which lasts 6 seconds per 1 pc of relay, which is 318 seconds per 53 pieces, and disassembly and reassembly must be added too, which is 10 seconds per piece and 530 seconds per 53 pieces. So the total time without alignment operation for 105 pcs of relays will be: 24,045 + 4,399 + 318 + 530 = 29,292 seconds. The production process time without alignment, but with sorting is 29,292 seconds, which is an improvement of 9.71% in comparison to the original 315 seconds per piece. 2.2.2 Solution proposal B In proposal, the alignment operation is replaced by a robot. The robot will do the operation for one relay in 35 seconds. That is 3,675 seconds for 105 pcs of relays. In this case, the time will be increased by an extension changing, which takes 60 seconds. Thus, the total alignment time with the robot is 3,735 seconds. In comparison to robot or conventional alignment, the robot-alignment operation time is lower than conventional alignment by 4,980 seconds. In this case, the loading to and unloading from the robot time should be included into the calculation. One piece of relay is loaded and unloaded for 12 seconds and for 105 pcs it is 1,260 seconds. After recalculation time with robot is in total: 3,735 + 1,260 = 4,995 seconds. Finally, one more time should be included – time to set the robot to another type of relay (it takes 2,625 seconds): 4,995 +2,625 = 7,620 seconds. The total time of the production process within the case solution B will be: 32,445 - 8,715 + 7,620 = 31,350 seconds. Case solution B represents an improvement of the process by 3.37% .

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