The Goal

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efficiencies have gone up, not down, as a result of what we've been doing in the plant. After we began withholding the release of materials and timing the releases according to the completed processing of heat-treat and the NCX-10, efficiencies dipped somewhat. But that was because we were consuming excess in- ventories. When the excess inventories were exhausted-which happened quickly as a result of the increase in throughput-effi- ciencies came back up again.

Then, two weeks ago, we implemented the new smaller batch sizes. When we cut batch sizes in half for non-bottlenecks, effi- ciencies stayed solid, and now it seems as though we're keeping the work force even more occupied than before.

That's because a really terrific thing has happened. Before we reduced batch sizes, it wasn't uncommon for a work center to be forced idle because it didn't have anything to process-even though we were wading through excess inventory. It was usually because the idle work center had to wait for the one preceding it to finish a large batch of some item. Unless told otherwise by an expediter, the materials handlers would wait until an entire batch was completed before moving it. In fact, that's still the case. But now that the batches are smaller, the parts are ready to be moved to the next work station sooner than they were before.

What we had been doing many times was turning a non- bottleneck into a temporary bottleneck. This was forcing other work centers downstream from it to be idle, which reflected poorly on efficiencies. Now, even though we've recognized that non-bottlenecks have to be idle periodically, there is actually less idle time than before. Since we cut batch sizes, work is flowing through the plant more smoothly than ever. And it's weird, but the idle time we do have is less noticeable. It's spread out in shorter segments. Instead of people hanging around with noth- ing to do for a couple of hours, now they'll have maybe a few ten- to twenty-minute waits through the day for the same volume of work. From everybody's standpoint, that's much better.

Still more good news is that inventories are at their lowest ever in the plant. It's almost shocking to walk out into the plant now. Those stacks and piles of parts and sub-assemblies have shrunk to half their former size. It's as if a fleet of trucks had come and hauled everything away. Which is, in fact, about what happened. We've shipped the excess inventory as finished prod- uct. Of course, the notable part of the story is that we haven't