assy cell tack times 1

[flash29]

what's the best way to calculate pph.?on a six person cell?? this is the first time i've needed to do a time study and i'm not sure of the best way, i've video taped the process and broke down components for the whole cell.

 

[BML]

If you only need to calculate pieces per hour, just measure the output of the cell/line over a period of time. However, I imagine that you're looking for ways to speed up the process. If the components of the cell (machines, workstations, etc.) are not very distinct, your job will be harder.<br>
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An easy way to find the "slow" station is to look for inventory, especially queue space. For example, if most of your stations have one or two pieces (or boxes, containers, etc.) in front of them but one station always has four, five, or six, then you've found the bottleneck. You can also look to see who is getting help the most. Many times in manual operations other less burdened operators will leave their station for a few seconds to help a co-worker "catch up". The person who needs the help is the bottleneck.<br>
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The goal then is to break the bottleneck. If the line balance can be altered to spread some of the work out, that will help. Everyone else's rate may go down, but the overall cell should improve. In my opinion, you should try to design the cell so that the first operation is the most time-consuming. Each successive operation should take a little less time. That way you can keep a (small) supply of raw goods at the first station, and should any problem occur further down the line, the rest of the operators/machines can catch up more easily.<br>
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Another way of improving throughput is to reduce your transfer size. For example, if you batch orders to reduce setups, only batch the first step. If you have a six-machine cell, the entire batch, say 100 pieces, could be in front of the first machine. But the other machines should not wait on all 100 pieces, but work on each piece as it finishes the first machine. The machine or standard time is the same, but you will reduce the amount of time for the entire order to go through (fairly substantially, actually).<br>
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For more help I'd suggest you read Eli Goldratt's "The Goal" series, especially the part about the Boy Scout hike.