Improvement of Material Flow in the Production and Supply Chain of ...

4.3.3 Increasing the operation time of bottlenecks
Operation time is relative stable under a certain circumstance. It will be varied with the
condition changes. If try to maintain machines in a more suitable schedule, the
operation time can be increased. There are many good examples in both academic
fields and practices. It is necessary and important to optimal terms of maintenance
(Peschanskii, 2006).
As data analyzed in chapter three, the operation time of the whole assembly line is half
of the TTF at present. There is a huge potential to increase the operation time. One of
the methods has been discussed in last section 4.3.2, but in fact that method is only
increase the percentage of operation time in the cycle time between the failures, the
operation time still keeps the same. Because there is no exact information of
maintenance about Hadelx, this solution only discussed from the point of the theory.
The results show in Table 4.8 means if keep others in the same situation only cut down
the time to repair, it is impossible to achieve the goal. Better maintenance can lead the
machines in more efficient and effective state, and then the operation time would
increase. As a result, the volume of production will increase. Assume the operation
time could double, simulate this condition by the model. Compared with the yield show
in Table 4.8, it is only increase about twelve percent, which still can not meet the goal of
2008.
4.3.4 Solution from integrative aspects in bottlenecks
Considering the reality and economy factors, the solution of the assembly line came out
to be a combination of the solutions mentioned above. Associate reduce the TTR to
different value with invest machines in the bottlenecks.
Table 4.9 lists the outputs in different assembles of data. From the table, once each of
station 8 in the main assembly line and station 2 in preassembly line has one more
machine, as well as reduce the TTR to approximately 20% of the TTF value, the
production volume per year (210 622 items) will exceed the demand in 2008, which is
200 000 items.
In fact the production volume by adding one more machine in station 8 of the main
assembly line together with reduction of TTR to limited value is already close to
200,000 per year, only about 1330 pieces behind. And these 1330 pieces can be
achieved by over working 24.6 hours, which three or four more shifts under certain
productivity.
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