The Goal: a process of Ongoing Improvement

parts we’re missing will reach assembly with no problem.’’
Jonah nodded and said, "That’s right. What you have to do is find a way to
release the material for the red parts according to the rate at which the
bottlenecks need material—and strictly at that rate.’’
Then I said, "Fine, but how do we time each release of material so it arrives
at the bottleneck when it’s needed?’’ Stacey said, "I’m not sure, but I see
what you’re worried about. We don’t want the opposite problem of no work
in front of the bottleneck.’’
"Hell, we got at least a month before that happens, even if we released no
more red tags from today on,’’ said Bob. "But I know what you mean. If we

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idle the bottleneck, we lose throughput.’’
"What we need,’’ I said, "is some kind of signal to link the bottlenecks with
the release-of-materials schedule.’’
Then Ralph, to my surprise, spoke up and said, "Excuse me, this is just a
thought. But maybe we can predict when to release material by some kind of
system based on the data we’ve kept on both the bottlenecks.’’
I asked him what he was getting at.
He said, "Well, since we started keeping data on the bottlenecks, I’ve been
noticing I’m able to predict several weeks in advance what each bottleneck
will be working on at a particular time. See, as long as I know exactly what’s
in queue, I just take the average setup and process times for each type of part,
and I’m able to calculate when each batch should clear the bottleneck.
Because we’re only dealing with one work center, with much less
dependency, we can average the statistical fluctuations and get a better degree
of accuracy.’’
Ralph went on to say that he knows from observation it takes about two
weeks, plus or minus a day or two, for material to reach the bottlenecks from
the first operations.
"So by adding two weeks to the setup and process times of what’s in queue at
the bottleneck,’’ said Ralph, "I know how long it will take until the
bottleneck is actually working on material we release. And as each batch
leaves the bottleneck, we can update our information and calculate a date
when Stacey should release more red-tag material.’’
Jonah looked at Ralph and said, "that’s excellent!’’
"Ralph,’’ I said, "that’s terrific. How accurate do you really think we can be
with this?’’
"I’d say we’d be accurate to within plus or minus a day,’’ he said. "So if we
keep, say, a three-day stock of work-in-process in front of each bottleneck,

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we should be safe.’’
Everyone was telling Ralph how impressed they were when Jonah said, "But,
in fact, Ralph, you can do much more than that with the same information.’’
"Like what?’’ asked Ralph.
Jonah said, "You can also attack the inventory problems in front of
assembly.’’
"You mean we not only can do something about excess inventory on the
bottleneck parts, but on the non-bottleneck parts as well?’’ I asked.
"Exactly,’’ said Jonah.
But Ralph said, "Sorry, folks, I’m not sure how I’d do that.’’
Then Jonah explained it to him—and all of us. If Ralph can determine a
schedule for releasing red-tag materials based on the bottlenecks, he can also
determine a schedule for final assembly.
Once he knows when the bottleneck parts will reach final assembly, he can
calculate backwards and determine the release of the non-bottleneck
materials along each of their routes. In this way, the bottlenecks will be
determining the release of all the materials in the plant.
I said, "You know, that’s going to produce the same effect as moving the
bottlenecks to the head of production, which is what I’d intended for us to
do.’’
“Yeah, it sounds good,” said Ralph. “But I have to warn you, I can’t say how
long it’ll take before I can do all that. I mean, I can have schedule for the red-
tagged materials worked out in a fairly short order. The rest of it will take
awhile.”
"Aw, come on, Ralphie,’’ said Bob, "a computer wiz like you ought to be
able to crank that out in no time.’’

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"I can crank something out in no time,’’ said Ralph, "but I’m not going to
promise it’ll work.’’
I told him, "Relax; as long as we ease the load on the milling machines, we’ll
be okay for the short haul. That’ll give you the time to get something basic in
place.’’
"You may feel you have the time now to relax,’’ said Jonah, "but I have to
catch a plane for Chicago in thirty-five minutes.’’ "Oh, shit,’’ I muttered,
automatically glancing at my watch.
"I guess we’d better move.’’
It was not a graceful parting. Jonah and I ran out of the building, and I broke
numerous speed limits—without incident—getting him to the airport.
"I have, shall we say, a special interest in plants like yours,’’ said Jonah. "So
I’d appreciate it if you’d keep me informed of what happens.’’
"Sure,’’ I told him. "No problem. In fact, I’d planned on it.’’ "Good,’’ said
Jonah. "I’ll be talking to you.’’
And with that he was out of the car and, with a wave, was sprinting through
the terminal doors. I didn’t get a call, so I suppose he made it.
When I go to work the next morning, we have a meeting about how to
implement this approach. But before we can get down to talking about it, Bob
Donovan starts waving a red flag at us.
"You know, we could be walking into a big problem,’’ says Bob.
"What’s that?’’ I ask.
"What happens if efficiencies all over the plant go down?’’ he asks.
I say, "Well, I think that’s a risk we’ll have to take.’’

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"Yeah, but it sounds like we’re going to have a lot of people idle around
here if we do this,’’ says Bob.
"Yeah, we might have some people idle from time to time,’’ I admit.
"So are we just supposed to let everyone stand around out there?’’ asks Bob.
"Why not?’’ asks Stacey. "Once the somebody is already on the payroll, it
doesn’t cost us any more to have him be idle. Whether somebody produces