Patty and the Professor: The Twiddler


It’s been a while. Let’s look in on Patty…

Patty stared, bleary eyed, at her laptop screen. It was the day after the election. She and Rob were following the election closely as a “statistical thinking” exercise. They had met at a conference with The Professor in late October and agreed that following the election would test their statistical thinking skills. They established beforehand that they would not discuss who they favored, just the data.

All agreed that Mitt Romney had a greater challenge than President Obama.

As Rob said, “Of the six most populated states, even the Republicans agree that Obama will win California (1), New York (3), Illinois (5), and Pennsylvania (6). Romney is only a shoe-in for Texas (2). Only Florida (4) is a toss up.”

“I thought some analysts were saying that Pennsylvania is in play,” The Professor commented.

“They’re dreaming,” Patty said with conviction. “Pennsylvania has too many big cities; typical Democrat strong holds,” she continued.

“Many pollsters have 255 electoral votes in Obama’s column and only a little over 200 for Romney. It’s hard to see a Romney path to victory. It is statistically unlikely he could win all of the swing states” Rob added.

The Professor beamed as he listened to his protégés intelligently analyze and argue the situation. They all agreed that it was hard to understand why many were referring to it as a close race, although voter turnout could change everything.

As election night went on, Patty felt she could call the election at 8PM EST. However, she was sympathetic that the networks needed a high level of certainty. The major networks were finally calling it at 10PM. When they did, Romney was ahead in the popular vote by about 1 million. Patty chuckled to herself, when a renowned TV anchor commented that it might be a governing challenge to Obama to win the electoral college and not the popular vote. Clearly he had not factored in the fact that, although California was “called” for Obama around 10PM EST, it was called with only a few percent of the votes in. The networks were using exit polls and statistical analysis to make a projection. By the time all of the west coast votes were counted, Obama will comfortably win the popular vote – because of California’s large population. Patty thought this should be obvious to the pundits.

Patty had stayed up until about 11PM to watch the results. It was comforting that her analysis was spot on. However, she was so “wound up” that she couldn’t fall asleep and she was now paying the price.

As her attention shifted back to the email she was writing. Suddenly, she was jarred by a loud, cheerful voice.

“Hey kiddo, pack your bags, looks like we’re on the road again,” Pete said loudly.

As usual Patty thought. “How does Pete always know these things before I do? I’m the boss!”

“What’s the scoop?” Patty asked.

“Remember our facility in Ohio? They are having wave soldering yield and throughput problems,” Pete answered.

“What!” Patty shouted. “We spent a lot of time there six months ago optimizing their wave soldering operation and teaching them the appropriate use of solder preforms. What happened?”

“Not sure,” Pete responded. “I thought we worked really well with their team and developed a good process. It seemed to me it was one of the more productive projects I was involved in in quite awhile.”

“And you didn’t even offend any of the senior managers,” Patty teased.

Pete chuckled but his cheeks did turn a little red. Pete was a terrific process engineer, but he had a little bit of a short fuse, although he was usually right.

“In talking to some of my buddies there, they told me that senior management hired a very senior fellow who is considered an expert in wave. Strangely, things fell apart right after he joined,” Pete explained.

“Well, you are on your own for this one. I’ve got a number of family commitments over the next two weeks,” Patty said with a little sadness in her voice. Patty enjoyed these types of challenges. “As soon as I get the official request, you’ll be on your way,” Patty said. “Oh, and don’t offend anyone,” she teasingly finished.

As Pete left her office, she checked her emails. Sure enough, there was a note from Mike Madigan asking her to intervene in this wave soldering problem.

Two days later Pete was in ACME’s Ohio facility sitting in the office of Pam Olinski, the site’s quality manager.

“Pete, I’m so glad you could come. Three months ago our wave soldering first-pass yield was 95% and our production was about 2,000 boards per day. Yield is now 90% and production is off 15%. Help!” Pam said.

“Tell me about the new guy,” Pete inquired.

“Fred Castle; he has very impressive credentials, but he has been running the wave process like a dictator. He stops the process a lot to adjust the wave machine. I think he will be offended that you are here to audit the process,” Pam finished.

Because of this concern, they agreed that it might be best to have Pete initially view the process from afar. They decided that Pete would be given an operator’s smock and walk around the shop floor for half a day or so.

As Pete arrived on the shop floor, almost immediately he saw Fred stop the wave machine and make some adjustments. While making the adjustments, Fred held a board in his hand — and he looked at occasionally. After the wave machine was running again,

Pete saw that Fred looked carefully at every board. Pete saw one of the wave operators was going on a break. Pete remembered Molly Stark from his visit to optimize the wave process six months ago, so he stopped her and ask if she could join in for lunch.

The morning passed quickly, and Pete was off to lunch with Molly. As Pete had suggested, Molly brought another operator, Chuck Petrus to lunch. Pete insisted on treating, so Molly and Chuck left their brown bags behind.

In total, Fred stopped the line four times during the almost 4 hours of Pete’s observations. Each time he made adjustments on the wave machine.

After exchanging pleasantries Pete asked, “Why was that fellow stopping the wave line so often?”

Molly got quite animated and answered, “That’s Fred Castle, the supposed wave genius. He stops the line every time there is a defect and adjusts the wave machine parameters. A number of us complained to him that he shouldn’t make adjustments on the machine that with just one fail. That’s what you taught us.”

“What did he say?” Pete asked.

“ ‘I’ve forgotten more about wave soldering than you will ever know.’ No one has said a word since,” Chuck responded.

“You and Patty taught us about special cause and common cause variation. I don’t think Fred understands that,” Molly commented.

“He’s also a knob twiddler,” Chuck added.

Does Fred know the difference between common and special cause variation? Is that the root of the yield and throughput problems? What is a knob twiddler? Stay tuned to find out.

Patty on Call

Let’s see how Patty is doing with the latest crisis …

Upon hearing Claire Perkins inform her that Rob was in the hospital, Patty froze and her face looked ashen. She quickly recovered and got her cell phone out to call Rob’s mother.

“Mom, what has happened to Rob?” Patty said, her voice quavering a little.

“He hurt his back at the gym, he can hardly walk. He collapsed under a heavy barbell. His head was injured too. He was unconscious for five minutes. I’m almost at the hospital now,” Rob’s mother, Hilde Gunther replied.

“I’ll see you there,” Patty said.

Both Sam and Mike insisted that someone take her to the hospital, but Patty refused.

Patty looked at her watch, it was 9AM. Rob was working a “swing shift” for six weeks and didn’t have to go into work until 10AM, so he went to the gym from 7:30 to 9AM most days. Patty had been teasing Rob that his workouts were getting too vigorous. She knew he was trying to snatch over 250 pounds as he was in a friendly competition with one of his friends, Fred, to see who would be the first to accomplish this significant feat. She wondered if this goal led to his accident.

The drive seemed to take forever, but soon she was at his emergency room bed. Rob was awake but his face was black and blue.  Patty didn’t notice her mother-in-law, as she quickly ran to Rob’s side.

“Rob, what happened?” Patty cried.

“The good news is, I snatched 250!” he chuckled, which caused him to grimace in pain. “It was 260 pounds that was my downfall, I collapsed under the weight,” Rob went on.

“How bad are your injures?” Patty asked, a little frustrated with Rob’s levity.

“My back hurts so much, I can hardly walk, my face just looks bad. I’m going for an MRI in a few minutes, they’re worried I might have a slipped disk,” Rob answered, becoming much more serious.

Just then an MRI tech came.

“Well Mr. Gunther, we are going to squeeze you in, so I need to put you ‘On Deck’ for an MRI that opens up. Realistically, it could be two or three hours,” the tech commented.

Both Patty and his mother kissed Rob on the part of his head that wasn’t black and blue as he left. After Rob was taken away, Patty chatted with her mother-in-law for about 30 minutes.

Even though to some people it would seem strange, Patty had a way of compartmentalizing things, she knew she could not help Rob, except to pray for him which she had already done. So, she decided to do some work on her laptop. Fortunately the hospital had WiFi.

Patty had some unfinished business from what she learned on her trip investigating NMAC/I/O. She wrote an email to the GMs of the sites using that cheaper solder paste that had the response to pause problems or that required kneading before being used, suggesting that they change to one of two corporate-approved pastes that didn’t have these issues. She also wrote a note to the people that were using a full wavesoldering process for a PWB that had only two through-hole components, saying solder preforms should be used with the reflow process.

As Patty finished the emails, she observed the activities of the MRI section of the hospital where she was waiting. It occurred to her that this was a process, just like assembling electronics. Instead of stencil printers and component placement machines, there was an MRI machine. There were techs that ran the MRI machines, just as there were operators on an SMT line. The nurses were like the process engineers, and there were some medical doctors that were like mangers and execs at her company. Instead of producing electronics, the MRI section was producing MRI scans. There was little difference.

Patty got curious and she decided to ask the scheduling assistant a few questions.

“Excuse me, my husband is getting an MRI and I have a few questions,” she asked Sara Carter the assistant.

“Sure,” Sarah said, “go ahead.”

“About how much does an MRI scan cost?” Patty asked.

“It varies depending on the extent of the scans needed, but $3,000 is a good estimate,” Sarah responded.

Patty asked more questions and learned that there were 5 MRI units and she assessed the headcount and floorspace needed to support the MRI unit. She also found out that each of the 5 MRI units averaged 9 scans per day. It then occurred to her that she could use ProfitPro to estimate the cost of a typical MRI scan. Under The Professor’s tutelage she has gotten quite good at estimating burden labor rates, etc, which would be needed for the calculation. She got her laptop out and using ProftiPro, in a few minutes estimated that the hospital’s cost of an MRI scan should be only $390!

“Why does it cost our insurance $3,000?” she thought.

It then occurred to her that her good friend from her days at Tech, Emily Chen, was a radiology resident at the hospital. She decided to send her a note and, in addition to telling her about Rob, ask about the MRI scan cost.

After sending the email, she asked her mother-in-law if she would like to get a cup of coffee. In a short time, they were heading to the hospital cafeteria. Before they left, they found out that Rob was just starting his 45-minute MRI scan.

Fifteen minutes later they returned, and Patty was surprised that she had already received an answer from Emily.

“Patty, I’m so sorry to hear about Rob. You probably won’t hear the official news on his MRI until tomorrow, but I will take a look at it and call you later today. BTW, my boyfriend works in the finance department here. I’ll find out about the cost. But, your numbers sound way off.”

Twenty minutes later Rob was finished. His doctor had given him some pain killers and muscle relaxers, so Rob was a little more comfortable, but the doctor wanted Rob to stay overnight for observation. Rob soon fell asleep from the medication. Patty decided to stay with Rob and by 4PM, she asked her mother-in-law if she could pick the boys up from day care.

At 4:30 PM another email arrived from Emily.

“Patty, good news. I looked at Rob’s MRI scan and it looks fine. He probably just severely strained a muscle. He’ll be as good as new in a month or so” Emily’s note began. Emily’s note went on, ”My boyfriend looked up the cost for the hospital to run an MRI scan. You were close, it costs $410. Neither of us can believe it. Where does the extra $2600 go?”

Dr. Ron note: I have done some investigations into MRI scan costs. As surprising as it sounds, these numbers are about right, the base cost for a hospital to perform an MRI scan is in the $400 range, but they have to charge $3,000 to break even. Considering that many hospitals are non profits and are losing money adds to the confusion.  At this point, I don’t claim to understand the cost structure of running a hospital, but one would think that one of the most critical questions in the current healthcare cost crisis in the United States, would be to understand why $3,000 must be charged for a $400 procedure to break even.  


A New Assembly Metric

Patty arrived at work an hour early to prepare for her meeting with ACME CEO Mike Madigan. Nineteen days ago he had asked her to develop an electronics assembly metric that would correlate with profitability. This metric would, in turn, be able to help pinpoint opportunities for improvement. He gave her 3 weeks, so she was two days early. Mike was in town to meet with Sam Watkins, the local plant manager, so he ordered that they meet.

Patty had quickly identified non-material assembly cost per I/O (NMAC/I/O) as a good metric candidate. She went to five of ACME’s plants and, after a day or two at each one, she collected all the data she needed to prove her point. Rob helped by writing an Excel macro that would calculate NMAC/I/O and plot it versus profitability. The correlation coefficient was an outstanding 0.983.

While visiting the five factories, she tried to learn why those that had a poor NMAC/I/O were performing poorly. After a little checking, she and Pete discovered that the poor performing sites typically had lines that were not time balanced, had slow component placement machines, and occasionally had very slow printers or solder paste with poor response to pause. There was even one plant that was using a full wave solder process, when only eight solder preforms would have done the job in the reflow process. None of these “problems” would show up if you were only tracking line uptime. In light of this situation, she also developed a plan to use NMAC/I/O to identify and implement opportunities for improvement.

As Patty headed toward Sam’s office, Sam’s administrative assistant invited Patty into the conference room to allow Patty to get her laptop set up. Just as she finished setting up and her Powerpoint presentation was on the screen, Sam and Mike walked in.

“Coleman, we’re counting on you to take us to the next level,” Mike said a little gruffly, “so let’s get this show going.”

Patty looked at Sam and could tell that Sam was uncomfortable with his boss’s abrupt demeanor.

“I performed quite a bit of research and concluded that non-material assembly cost per I/O is the best metric,” Patty started.

“That’s great Coleman, but what the hell is non-material whatever you said,” Madigan interrupted.

Patty’s cellphone vibrated, but she ignored it.

“Non-material assembly cost per I/O is the total cost of running a factory less the components, hardware, and PWBs used. Some people call this the conversion cost,” Patty answered.

“If you think about it, it is almost obvious that this is the best metric,” Patty went on, “as it measures all the non-material cost divided by how much we produce.”

“I get it,” said Sam. “We are producing I/Os or solder joints, we measure the total cost to make solder joints and divide by the number of solder joints. It’s that simple.”

“Precisely,” Patty responded.

“I understand now why uptime alone wasn’t a complete metric. You can be up and running, but be doing it inefficiently,” Mike said with a rare smile on his face.

Patty’s cellphone vibrated again.

“Exactly,” Patty commented.

“OK, so we are going to measure NMAC/I/O,” Mike commanded, “How does it correlate to profit?”

“It is nearly perfect,” Patty said.

They continued their discussions and reviewed Patty’s plan to improve productivity at the sites with a high NMAC/I/O. Patty would take the lead on this effort.

As Patty got up to leave, Mike commanded, “Oh, and Coleman, find out why so few people use NMAC/I/O.”

Patty thought this was something to discuss with the Professor.

As Patty walked out of Sam’s office, Clare Perkins, Sam’s Admin stopped her.

“Ms. Coleman, your mother-in-law called, Rob has been taken to the hospital,” Clare said.