여러분,
Business was good at ACME. Even in these challenging times, the company’s three assembly lines could not keep up with demand. John, the manger of the assembly lines, decided to request the funds for an additional assembly line. A member of his team, Patty, suggested he might want to consult “The Professor,*” before getting a new line. The Professor taught a course on line balancing that Patty took at the SMTAI conference last summer. Line balancing is an important part of optimizing productivity in electronic assembly. A balanced line ensures that the component placement process, usually the “constraint,” is the fastest possible by assuring that each placement machine spends the same amount of time placing components. If any machine is waiting for the others, assembly time is being wasted. In a sense line balancing is an application of Goldratt’sTheory of Constraints . John remembered that when Patty applied what she learned from The Professor, throughput increased 25%. Unfortunately, Patty did not attend The Professor’s other class on “Increasing Line Uptime.”
John decided to have a chat with Patty about The Professor. “Patty, why do you think I should consult with The Professor, about getting a new line?”
“Well John, perhaps with some effort to improve our uptime, we wouldn’t have to buy another line,” said Patty.
“Patty, that’s a good point,” replied John.
Patty contacted The Professor and he agreed to fit ACME into his hectic schedule. Upon his arrival, The Professor was given a tour. As part of the tour he was shown the process that ACME used to minimize changeover time between jobs. The Professor appeared to be impressed. After the tour, The Professor asked if a brief meeting could be held with the engineers and managers to discuss the situation.
"평균 대기 시간은 얼마나 되나요?" 교수가 학생들에게 물었습니다.
There was some hemming and hawing, finally Pete, the senior process engineer replied, “I’d say at least 95%, we work our fannies off out there.” There was a murmur of agreement from the 9 or 10 people in the room.
Finally John spoke up, “Professor, what is your definition of uptime?”
The Professor responded, “Simply the percent of time an assembly line is running.” Pete again responded that 95% was the right number.
The Professor asked for some production metrics and performed some calculations on his laptop. In a few moments he commented, “From the data you gave me, I estimate that your average line uptime is about 10%.”
이 말을 들은 피트는 얼굴이 빨개졌고, 특히 패티가 그의 귀에 속삭이면서 "내가 말했잖아"라고 말하자 얼굴이 빨개졌습니다. 방 안의 소음이 너무 커져서 존은 폭동이 일어날지도 모른다는 걱정이 들었습니다. 교수가 발언을 요청했고 존은 큰 목소리로 진정해 달라고 요청했습니다.
“Let’s not become angry, perhaps my calculations are off. Why don’t we measure the uptime for a few weeks to be certain.”
“How do we do that?” asked Pete, his face still crimson.
“Each day one process engineer will go out to the lines every 30 minutes. If the line is running, he will put a 1 in an Excel® spreadsheet cell, if the line is not running a 0 will be entered,” responded the professor.” It was agreed that this will be done and The Professor will be back in two weeks.
Will Pete’s red face return to normal? Will the line uptime be 95%? Will Patty and Pete ever be on speaking terms again? Stay tuned for the next episode.
건배,
론 박사
* The Professor, as he is affectionately called by his many students, is a kindly older man who works at a famous university. Few know his real name. The Professor is an expert in process optimization.
