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Yoshihiro Mizutani et al. / Energy Procedia 89 (2016) 318 – 322
Each process should produces 100 sheets per minute with the same speed. 7KHVHWWLPHIRUHDFKSURFHVVLVPLQXWHV+RZHYHU when there is no color change in 1 st process, the set time will be 2 minutes. &RPSDUHWKHSDXVHGWLPHEHWZHHQWKHPHWKRG of batch production with common colors and the production method of preferentially proceed of purchase order with multiple processes. 3. Results There was 30 minutes increase in the color changing time in the 1 st Process. However, there was 150 minutes reduction in the waiting time for the 2 nd and the 3 rd Processes,which means that the production time for a working day was reduced for 120 minutes, in other words reduced for 21%. (Table 3) Units and Measurements
Minute Step number Total Minute Step number Total Common Production Method Production Method of Jpacks
Table 3
Difference
Color change in the 1st Process Set change in the 1st Process Set change in the 2nd Process Set change in the 3rd Process Waiting time in the 2nd Process Waiting time in the 3rd Process
3 2 5 5
5 15 3 15 30 2 10 50 5 5 25 5 5 50 0 10 100 0 30 300 10
15 45 30 15 30 0 10 50 0 5 25 0 0 0 -50 0 0 -100 30 300 0
10 10 10
Total Operation Time
Production Time of a Working Day
570
450 -120
3.1. Creation of All-Round Worker and Holding Process with Many Steps When the production method of preferentially proceed of purchase order with multiple processes is realized, the idle times that are normally dispersed throughout the production process are gathered together toward the end of each process (gray cells). Therefore, the workers are abled to engage with the steps for other processes. At this time, it will be possible to allocate more workers to the process that is normally a bottleneck, and can reduce the burden of
the works and adjust the discrepancy in workload among the workers. 4. Production method with every process conducted in parallel
Production method with every processes conducted in parallel is the method where all the processes are operated at the same time, and the production is completed in one go from the beginning to the end. In the common method, there are moments where the work-in-progress piles up. But this proposed method conducts production straight from the beginning to the end. Therefore, it was named production method with every processes conducted in parallel. For instance, in the production of 12,000 sheets for corrugated cardboard boxes requiring three processes, if 100 sheets can be produced in every minute, each process requires 120 minutes. In the common production method (Fig. 1 (b)), the work-in-process is stopped between each process, and its average production L/T is approximately 3 days. On the other hand, the proposed production method with every processes conducted in parallel (Fig. 1), the time lag between each process is only for 1 pallet, if 1 pallet holds 500 sheets, the 2 nd Process can be started only after approximately 5 minutes. Moreover, even if it takes extra 5 minutes for transportation and preparation, the 2 nd Process can be started after 10 minutes in total, and the 3 rd Process can be started approximately 10 minutes after that. Therefore, the production L/T is 150 minutes (Preparation process: 120min + 10min × 3 times).
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