VELOCITY - DEE JACOB [118]
“How?” asked Garth. “Give him two dice like the rest of us?”
“No, you don’t want to do that, because then you’re back to all the issues and problems of a balanced line.”
“Give Murphy two dice and everybody else three dice,” said Sarah.
“You could do that,” said Tom, “but Elaine and Amy would freak out.”
“That would be very expensive,” said Amy, “and we would have to be absolutely sure that the long-term market would support that investment.”
“You improve Murphy’s yield,” Wayne suggested.
“That’s it!” said Tom. “You focus all your Lean and Six Sigma techniques on the constraint. Not necessarily on the constraint itself, but on things that improve the constraint’s operations.”
“Okay, I see,” said Wayne, with a note of enthusiasm.
“Instead of trying to eliminate waste everywhere, you target the waste that most affects the constraint’s performance. Instead of improving everything, you improve whatever improves the yield of the constraint.”
“Which would be generally, I think, much more affordable than adding capacity everywhere and improving everything,” said Amy.
“To do that in terms of the dice game,” said Tom, “we’re going to symbolically improve Murphy in Round Four, but improving his one die. In this round, everything stays the same as in Round Three – twelve penny buffer inventory for Murphy, no dice for Amy – but when Murphy rolls a one or a two, it’s going to equal a four. If he rolls a three or a four, it’s going to equal a five. And if he rolls a five or a six, it will be the equivalent of a six.”
“So you’re eliminating all the low rolls,” said Wayne. “In a sense, you’re eliminating the rolls that waste a turn on low output.”
“Exactly,” said Tom. “All right. Pass the pennies around. Everybody set?”
The fourth round was by far their best. In the first “week” of the round, they moved twenty-three pennies across the finish line. In the second, twenty-four; then another twenty-four cents in the third game week. And during the fourth week, a fabulous twenty-six cents were swept into the finish pile. The grand total: ninety-seven cents.
As for inventory, they began with twenty-eight pennies in all the queues, and they finished with thirty-two pennies in process. The queue in front of Murphy dropped to six for two turns in a row – during their fourth week, their most productive – but never went below.
“By the way,” said Tom, “there is a name for what we did in the Third and Fourth Rounds. It’s called Drum, Buffer, and Rope. The Drum is the system constraint – Murphy, in this case. The Buffer is the time required to deposit materials in queue for the constraint to process. And the Rope is the communication connection to the gate that releases those materials for processing. So Drum, Buffer, Rope – or DBR, as it’s known.”
As everyone else pondered the implications of what had been demonstrated, Tom got to his feet.
“So … I hope that helped,” said Tom. “Sorry, but I’ve got to run. I’ve got a hot date with a fishing boat down on the Gulf.”
“I’ll walk out with you,” Amy said.
Outside, as they went to his car, she slipped her arm around his.
“Where you going?” she asked.
“The Keys. A Marine buddy of mine called. Said he’s taking his boat out, doing a little fishing, and wanted some company. I knew you’d be working, so …”
“I thought you’d be around tonight,” Amy said, disappointed. “When will you be back?”
Tom shrugged his shoulders. “A couple of days. I’ll call you.”
Then a quick kiss, and he was in the Mustang and gone.
Inside, Amy tried to clear Tom from her mind. The others had used the interlude to take a break; the dining room table was deserted when she returned. She went to the kitchen where she had set up refreshments, and was pouring a glass of ice water when Sarah appeared at her elbow.
“Tom seems like a good man,” Sarah said quietly.
“He is,” said Amy. “When he’s around.”
Elaine gravitated toward them.
“Does he always go off like that?” she asked.
“He has a restless streak,” said Amy.
“If Bill did