furious complaints. It's one thing to be consistently bad; the clients are used to it and they protect themselves by stocks or time buffers. But now we have spoiled them, they are already used to our good perfor- mance.
This is much worse than I've imagined. It might ruin the plant.
How did it happen? Where did I go astray?
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'How come?' I ask them.
'I told you,' Bob says. 'Order no. 49318 is stuck because of...'
'No Bob,' Stacey stops him. 'It's not the details that are important. We should look for the core problem. Alex, I think that we simply accepted more orders than we can process.'
'That's obvious,' I say. 'But how come? I thought we checked that the bottlenecks have enough capacity. We also checked your seven other problematic work centers. Did we make a mistake in the calculations?'
'Probably,' Bob answers.
'Not likely,' is Stacey's response. 'We checked and double checked it.'
'So?'
'So, I don't know,' Bob says. 'But it doesn't matter. We have to do something now, and fast.'
'Yes, but what?' I'm a little impatient. 'As long as we don't know what caused the situation, the best we can do is to throw punches in all directions. That was our old mode of operation. I had hoped that we learned better.'
I accept their lack of response as agreement and continue, 'Let's call Lou and Ralph and move into the conference room. We must put our heads together to figure out what is really going on.'
'Let's get the facts straight,' Lou says after less than fifteen minutes. 'Bob, are you convinced that you need to keep using so much overtime?'
'The efforts of the last few days have convinced me that even with overtime we are going to miss due dates,' Bob answers.
'I see,' Lou doesn't look too happy. 'Ralph, are you con- vinced that at the end of the month, in spite of the overtime, we are going to be late on many orders?'
'If we don't find a smart way to solve this mess, without a doubt,' Ralph answers confidently. 'I can't tell you the dollar amount, that depends on Bob and Stacey's decisions of how much overtime to use and which orders to expedite. But it is in the neighborhood of over a million dollars.'
'That's bad,' Lou says. 'I'll have to redo my forecast.'
I throw him a murderous look. That is the major damage that he sees? Redo the forecast!
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'Can we address the real issue?' I say in a freezing voice. They all turn to me waiting.
'Listening again to what you're saying, I don't see a major problem,' I say. 'It is obvious that we tried to swallow more than we can chew. What we have to do is to determine by how much and then compensate. It is as simple as that.'
Lou nods his head in approval. Bob, Ralph, and Stacey con- tinue to look at me with poker faces. They even look offended. There must be something wrong in what I've said, but I can't see what.
'Ralph, by how much are our bottlenecks overloaded?' I ask.
'They're not overloaded,' he says flatly.
'No problem there,' I conclude. 'So let...'
'He didn't say that,' Stacey cuts me off.
'I don't understand,' I say. 'If the bottlenecks are not over- loaded then...'
Maintaining an expressionless face she says, 'From time to time the bottlenecks are starved. Then the work comes to them in a big wave.'
'And then,' Bob continues, 'we don't have a choice but to go into overtime. That's the case all over the plant. It looks like the bottlenecks are moving all the time.'
I sit quietly. What can we do now?
'If it were as easy as determining some overloads,' Stacey says, 'don't you think we would easily solve it?'
She is right. I should have more confidence in them.
'My apologies,' I mutter.
We sit quietly for a minute. Then Bob speaks up, 'We can't handle it by shuffling priorities and going into overtime. We've already tried that for several days. It might help save some spe- cific orders but it throws the entire plant into chaos and then many more orders are in trouble.'
'Yes,' Stacey agrees. 'Brute force seems to push us more and more into the spiral. That's why we asked for this meeting.'
I accept their criticism.
'Okay, it's obvious that we have to approach it systematically Anyone got an idea where to begin?'
'Maybe we should start by examining a situation where we have one bottleneck.' Ralph suggests hesitantly.
'What's the point?' Bob objects. 'We now have the opposite.
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We are facing many, traveling bottlenecks.' It's apparent that they've had that discussion before.
I don't have any other suggestion, nor does anybody else. I decide to gamble on Ralph's hunch. It worked in the past.
'Please proceed,' I say to Ralph.
He goes to the board and takes the eraser.
'At least don't erase the five steps,' Bob protests.
'They don't seem to help us much,' Ralph laughs nervously. 'Identify the system's constraints,' he reads. 'That is not the problem now. The problem is that the bottlenecks are moving all over the place.'
Nevertheless, he puts the eraser down and turns to the flip chart. He draws a row of circles.
'Suppose that each circle represents a work center,' he starts to explain. 'The tasks are flowing from the left to the right. Now, let's suppose that this one is a bottleneck,' and he marks one of the middle circles with a big X.
'Very nice,' says Bob sarcastically. 'Now what?'
'Now let's introduce Murphy into the picture,' Ralph re- sponds calmly. 'Suppose that Murphy hits directly on the bottle- neck.'
'Then the only thing left to do is to curse wholeheartedly,' Bob spits. 'Throughput is lost.'
'Correct,' Ralph says. 'But what happens when Murphy hits anywhere before the bottleneck? In such a case, the stream of tasks to the bottleneck is temporarily stopped and the bottleneck is starved. Isn't this our case?'
'Not at all,' Bob brushes it away. 'We never operated that way. We always make sure that some inventory accumulates in front of the bottleneck, so when an upstream resource goes down for some time, the bottleneck can continue to work. As a matter of fact, Ralph, we had so much inventory there that we had to choke the material release to the floor. Come on,' he says impatiently, 'that is exactly what you're doing on your computers. Why do we have to regurgitate what we all know by heart?'
Ralph goes back to his seat. 'I just wondered if we really know how much inventory we should allow to accumulate in front of the bottlenecks?'
'Bob, he has a point,' Stacey remarks.
'Of course I have,' Ralph is really annoyed. 'We wanted three days' inventory in front of each bottleneck. I started with
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