The Goal: a process of Ongoing Improvement

Parts are made in a sequence of steps. Machine A has to finish Step One
before Worker B can proceed with Step Two. All the parts have to be
finished before we can assemble the product. The product has to be
assembled before we can ship it. And so on.
But you find dependent events in any process, and not just those in a factory.
Driving a car requires a sequence of dependent events. So does the hike
we’re taking now. In order to arrive at Devil’s Gulch, a trail has to be walked.
Up front, Ron has to walk the trail before Davey can walk it. Davey has to
walk the trail before Herbie can walk it. In order for me to walk the trail, the
boy in front of me has to walk it first. It’s a simple case of dependent events.
And statistical fluctuations?
I look up and notice that the boy in front of me is going a little faster than I
have been. He’s a few feet farther ahead of me than he was a minute ago. So I
take some bigger steps to catch up. Then, for a second, I’m too close to him,
so I slow down.
There: if I’d been measuring my stride, I would have recorded statistical
fluctuations. But, again, what’s the big deal?
If I say that I’m walking at the rate of "two miles per hour,’’ I don’t mean I’m
walking exactly at a constant rate of two miles per hour every instant.
Sometimes I’ll be going 2.5 miles per hour; sometimes maybe I’ll be walking
at only 1.2 miles per hour. The rate is going to fluctuate according to the
length and speed of each step. But over time and distance, I should be
averaging 
about two miles per hour, more or less.
The same thing happens in the plant. How long does it take to solder the wire
leads on a transformer? Well, if you get out your stopwatch and time the
operation over and over again, you might find that it takes, let’s say, 4.3
minutes on the average. But the actual time on any given instance may range
between 2.1 minutes up to 6.4 minutes. And nobody in advance can say,
"This one will take 2.1 minutes... this one will take 5.8 minutes.’’ Nobody
can predict that information.

---

So what’s wrong with that? Nothing as far as I can see. Anyway, we don’t
have any choice. What else are we going to use in place of an "average’’ or
an "estimate’’?
I find I’m almost stepping on the boy in front of me. We’ve slowed down
somewhat. It’s because we’re climbing a long, fairly steep hill. All of us are
backed up behind Herbie.
"Come on, Herpes!’’ says one of the kids.
Herpes?
"Yeah, Herpes, let’s move it,’’ says another.
"Okay, enough of that,’’ I say to the persecutors.
Then Herbie reaches the top. He turns around. His face is red from the climb.
"Atta boy, Herbie!’’ I say to encourage him. "Let’s keep it moving!’’
Herbie disappears over the crest. The others continue the climb, and I trudge
behind them until I get to the top. Pausing there, I look down the trail.
Holy cow! Where’s Ron? He must be half a mile ahead of us. I can see a
couple of boys in front of Herbie, and everyone else is lost in the distance. I
cup my hands over my mouth.
"HEY! LET’S GO UP THERE! LET’S CLOSE RANKS!’’ I yell. "DOUBLE
TIME! DOUBLE TIME!’’
Herbie eases into a trot. The kids behind him start to run. I jog after them.
Rucksacks and canteens and sleeping bags are bouncing and shaking with
every step. And Herbie—I don’t know what this kid is carrying, but it sounds
like he’s got a junkyard on his back with all the clattering and clanking he
makes when he runs. After a couple hundred yards, we still haven’t caught
up. Herbie is slowing down. The kids are yelling at him to hurry up. I’m
huffing and puffing along. Finally I can see Ron off in the distance.

---

"HEY RON!’’ I shout. "HOLD UP!’’
The call is relayed up the trail by the other boys. Ron, who probably heard
the call the first time, turns and looks back. Herbie, seeing relief in sight,
slows to a fast walk. And so do the rest of us. As we approach, all heads are
turned our way.
"Ron, I thought I told you to set a moderate pace,’’ I say.
"But I did!’’ he protests.
"Well, let’s just all try to stay together next time,’’ I tell them.
"Hey, Mr. Rogo, whadd’ya say we take five?’’ asks Herbie.
"Okay, let’s take a break,’’ I tell them.
Herbie falls over beside the trail, his tongue hanging out. Everyone reaches
for canteens. I find the most comfortable log in sight and sit down. After a
few minutes, Davey comes over and sits down next to me.
"You’re doing great, Dad,’’ he says.
"Thanks. How far do you think we’ve come?’’
"About two miles,’’ he says.
"Is that all?’’ I ask. "It feels like we ought to be there by now. We must have
covered more distance than two miles.’’ "Not according to the map Ron
has,’’ he says.
"Oh,’’ I say. "Well, I guess we’d better get a move on.’’ The boys are already
lining up.
"All right, let’s go,’’ I say.

---

We start out again. The trail is straight here, so I can see everyone. We
haven’t gone thirty yards before I notice it starting all over again. The line is
spreading out; gaps between the boys are widening. Dammit, we’re going to
be running and stopping all day long if this keeps up. Half the troop is liable
to get lost if we can’t stay together.
I’ve got to put an end to this.
The first one I check is Ron. But Ron, indeed, is setting a steady, "average’’
pace for the troop—a pace nobody should have any trouble with. I look back
down the line, and all of the boys are walking at about the same rate as Ron.
And Herbie? He’s not the problem anymore. Maybe he felt responsible for
the last delay, because now he seems to be making a special effort to keep up.
He’s right on the ass of the kid in front of him.
If we’re all walking at about the same pace, why is the distance between Ron,
at the front of the line, and me, at the end of the line, increasing?
Statistical fluctuations?
Nah, couldn’t be. The fluctuations should be averaging out. We’re all moving
at about the same speed, so that should mean the distance between any of us
will vary somewhat, but will even out over a period of time. The distance
between Ron and me should also expand and contract within a certain range,
but should average about the same throughout the hike.
But it isn’t. As long as each of us is maintaining a normal, moderate pace like
Ron, the length of the column is increasing. The gaps between us are
expanding.
Except between Herbie and the kid in front of him.
So how is he doing it? I watch him. Every time Herbie gets a step behind, he
runs for an extra step. Which means he’s actually expending more energy
than Ron or the others at the front of the line in order to maintain the same
relative speed. I’m wondering how long he’ll be able to keep up his walk-run
routine.

---

Yet... why can’t we all just walk at the same pace as Ron and stay together?
I’m watching the line when something up ahead catches my eye. I see Davey
slow down for a few seconds. He’s adjusting his packstraps. In front of him,
Ron continues onward, oblivious. A gap of ten... fifteen... twenty feet opens
up. Which means the entire line has grown by 20 feet.
That’s when I begin to understand what’s happening.
Ron is setting the pace. Every time someone moves slower than Ron, the line
lengthens. It wouldn’t even have to be as obvious as when Dave slowed
down. If one of the boys takes a step that’s half an inch shorter than the one
Ron took, the length of the whole line could be affected.
But what happens when someone moves faster than Ron? Aren’t the longer
or faster steps supposed to make up for the spreading? Don’t the differences
average out?
Suppose I walk faster. Can I shorten the length of the line? Well, between me
and the kid ahead of me is a gap of about five feet. If he continues walking at
the same rate, and if I speed up, I can reduce the gap—and maybe reduce the
total length of the column, depending upon what’s happening up ahead. But I
can only do that until I’m bumping the kid’s rucksack (and if I did that he’d
sure as hell tell his mother). So I have to slow down to his rate.
Once I’ve closed the gap between us, I can’t go any faster than the rate at
which the kid in front of me is going. And he ultimately can’t go any faster
than the kid in front of him. And so on up the line to Ron. Which means that,
except for Ron, each of our speeds depends upon the speeds of those in front
of us in the line.
It’s starting to make sense. Our hike is a set of dependent events...in
combination with statistical fluctuations. Each of us is fluctuating in speed,
faster and slower. But the ability to go faster than average is restricted. It
depends upon all the others ahead of me in the line. So even if I could walk
five miles per hour, I couldn’t do it if the boy in front of me could only walk

---

two miles per hour. And even if the kid directly in front of me could walk
that fast, neither of us could do it unless all the boys in the line were moving
at five miles per hour at the same time.
So I’ve got limits on how fast I can go—both my own (I can only go so fast
for so long before I fall over and pant to death) and those of the others on the
hike. However, there is no limit on my ability to slow down. Or on anyone
else’s ability to slow down. Or stop. And if any of us did, the line would
extend indefinitely.
What’s happening isn’t an averaging out of the fluctuations in our various
speeds, but an