Author Archives: Dr. Ron

About Dr. Ron

Materials expert Dr. Ron Lasky is a professor of engineering and senior lecturer at Dartmouth, and senior technologist at Indium Corp. He has a Ph.D. in materials science from Cornell University, and is a prolific author and lecturer, having published more than 40 papers. He received the SMTA Founders Award in 2003.

Questions on Tin Whiskers

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Folks,

In a recent post, I shared my perspective on the pluses, minuses and neutral aspects of lead-free solder assembly. In the minus category, I listed tin whiskers. A few people commented that tin whiskers were the biggest concern in lead-free assembly. I have trouble understanding this perspective. I’m not saying these folks are wrong, just that I don’t understand their viewpoint.

First, let me say that I appreciate the concern for tin whiskers in mission critical electronics such as military, aerospace and medical. I am also sympathetic to the fact that, even though these types of electronics are exempt from RoHS, they may have to use RoHS compliant products because non-RoHS compliant products may not be available.

When I discuss the topic of tin whiskers, people will point me to NASA’s tin whisker failures website . However, when one goes to the site, there are only about twenty tin whisker fails referenced, many due to bright tin plate. Bright tin plate should never be used in mission critical electronics as it is virtually assured of producing tin whiskers. In addition, many of the articles referenced do not talk about tin whisker fails. Few if any fails are discussed relevant to RoHS (i.e. almost all fails discussed are prior to July 2006.)

I do not want to minimize the significance of tin whisker fails, some of them cost 100s of millions of dollars (e.g., satellite failures). In addition, there have been a few papers that have discussed the formation of tin whiskers even if mitigation techniques are used. Tin whiskers clearly can cause problems, but do not appear to be common, especially if mitigation techniques are used.

So here is my question, who knows of any verified tin whisker fails when tin whisker mitigation techniques were used? Tin whisker mitigation techniques typically use 2% bismuth or antimony in the tin, assure that the tin has a matte finish and use a nickel strike plating between the copper and the tin to minimize copper diffusion into the tin.

Surely if tin whiskers are a major concern, there should be many fails in the over $3 trillion worth of RoHS compliant electronics manufactured since July 2006.

Cheers,

Dr. Ron

Pluses and Minuses of Pb-Free Solder

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Folks,

I thought I would take a stab at listing the minuses, pluses, and “it’s a wash” aspects of assembling with lead-free (LF) solder. Here are my first thoughts. Please tell me what I missed or disagree.

Minuses

1.    Pb-Free requires higher reflow temperatures
The Tm for LF solders, in the 217-229C range, has created numerous challenges:

a.      PWB warpage and damage

b.      Component damage

c.      New defect modes such as graping and head-in-pillow defects (although concurrent reduction in solder paste deposit sizes for 0201 and 01005 passives and 0.3 mm CSPs also exacerbate these defects)

d.      Defects related to increased oxidation

e.      Increases in voiding

f.       Increases in tombstoning

2.      The higher cost of LF solder, mostly for wave soldering

a.      It’s not just the silver, tin is much more expensive than lead

3.      Poorer wetting of LF solders, creating the most significant challenges in wave soldering

4.      More rapid copper pad dissolution on PWBs in wave soldering

5.      LF solder attack of wave solder machine components

6.      LF reliability in harsh thermal cycle testing appears poorer than SnPb solders

7.      Tin Whiskers

It’s a Wash

1.      Short-term reliability in consumer product-type environments

2.      Protection of the environment if discarded products are improperly disposed of

a.      Lead in electronics has never been shown to cause a problem in land fills

3.      Since July 2006, about $3 trillion of products have been manufactured with LF solder, with no “the sky is falling”-type of problems

Pluses

1.      LF solder’s poor wetting enables finer lead spacings (see photo courtesy of Motorola)

a.      It may be argued that some modern electronic products (e.g., smartphones) could not be made with SnPb solder

2.      It is safer to recycle LF solders, especially if performed in a non-controlled environment
OK — your turn. Please comment.

Best Wishes,

Dr. Ron

Some Consensus on SAC

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Back in November, I posted comments on lead-free availability. In this post, I mentioned that I chaired a session at SMTAI on Alternate Alloys. At this session, Greg Henshall presented a paper on the  Low Silver BGA Sphere Metallurgy Project. This paper was a collaborative effort of six companies.  In addition, Richard Coyle presented an overview of the work of three companies titled “The Effect of Silver Content on the Solder Joint Reliability of a Pb-free PBGA Package.” Both projects evaluated Pb-free thermal cycle reliability as a function of silver content and compared the results to SnPb reliability.

Both papers concluded that, as far as 0oC to 100 oC thermal cycle reliability is concerned, in their experiments

SnPb < SAC105 < SAC305 < SAC405

Coyle’s presentation summed it up best: “Each of the SAC alloys outperformed the SnPb eutectic alloy in every test, including the long, 60 min. dwell time test. This tends to diminish the argument that SAC is less reliable than SnPb.”

To be clear, it was two papers by two different groups coming to the same conclusion. It would probably be a stretch to say that the conclusions of either group were “almost unique”.

Denny Fritz responded to this blog post with this point: “No one I know will dispute your ranking of SAC better than SnPb solder using the commercial temperature cycle Henshall uses – 0C to 100C. But, harsh environment electronics have to perform to either -40C or -55C, and most use a top end cycling temperature of 125C. IT IS IN THAT WIDE THERMAL CYCLE TESTING THAT SnPb outperforms SAC solders.”

Denny’s point is well- taken. I believe it can be said that SAC alloys have demonstrated acceptable reliability in commercial, non harsh environments (i.e., mobile phones, PCs, consumer electronics, etc.). However, it cannot be said that acceptable reliability for SAC has been established for military (RoHS exempt) and harsh (i.e., automobile engine compartment) environments.

A short time ago, Werner Engelmaier wrote an article on this topic (Global SMT, vol. 11, no. 1, January 2011, pp. 38-40), referring to my post he said: “Of course, ‘Dr. Ron’ selectively picks data agreeing with the point of view he held from the inception of the Pb-ban under RoHS on a plot with an expanded x-axis overemphasizing the differences and supporting a solder joint reliability ranking of SnPb < SAC105 < SAC305 < SAC405.”

Ouch! My motives were not quite so nefarious, I chaired a session and wanted to share the conclusions.

However, Werner makes good points in his article, data exist disagreeing with this reliability ranking and he suggests some good points on how to conduct reliability tests so that comparisons can be made between data sets.

In reading some of his other articles, I was delighted to find that we actually agree on the state of lead-free reliability in thermal cycle testing. Here is a statement of his circa 2008 (Global SMT, vol 8., no. 8, August 2008, pp. 46-48.): “It has been 2 years since the infamous ban of Pb-solders under RoHS. What have we learned? For solder joints, no dramatic differences in reliability are apparent. The data bases for LF-solders have grown, the favored LF-solders might be shifting, and no reliability model exists as of yet. Nevertheless, progress has been made.”

Best Wishes,

Dr. Ron

Recycled Products Limit Solderless Ideas

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Before the mid 2000s, electronics manufacturers had to be concerned with the challenges of innovation at a low cost. Failure to meet these requirements, resulted in unsuccessful products.  Sustainable design is a relatively new requirement for electronic manufacturers – in addition to all previous challenges. The EU’s WEEE and RoHS laws support sustainable design by virtually requiring that electronic products be recycled. Even products exempt from RoHS, such as medical devices and measuring & control equipment, must meet WEEE’s recycling requirements.

Some have argued that the recycling requirement exacerbates the rampant counterfeit component crisis. I am sympathetic to this argument, but the counterfeit component calamity must be solved another way. With the volume of scrap electronics that exists, the world needs safe and effective recycling, as can be seen in the accompanying photograph (National Geographic, January 2008).

I was reminded of this recycling requirement when I read of the soon-to-be-published book Solderless Assembly For Electronics (SAFE). The topic of the book is solderless technologies like the “Occam” process . When first announced, in August 2007, a number of people, including me, questioned the need for these types of processes and delineated some of the expected difficulties in implementing them. Since then, the need to recycle product is another significant challenge to these processes. Soldering enables relatively easy disassembly of PCBs. Most proposed solderless processes copper-plate components to create the equivalent of circuit traces, while the PCB function is built up. Thus, it is more difficult to disassemble a PCB with these types of processes, as the copper bonds melt at 1085°C, much too hot for components and the PCB.

It will be interesting to see how this recycling challenge and other issues facing solderless assembly processes are addressed in this book.

Dr. Ron

The Law of Averages

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Folks,

Patty had been working with engineering on a new product that needed a very precise and controlled volume of the stencil printed “brick” of solder paste on the PWB pads. The product had many 01005 passives and CSPs with 0.030″ spacings and the application was “mission critical.” So solder joint integrity was critical. The critical factor in obtaining this solder joint integrity was a consistent volume in the stencil printed brick. Her favorite solder paste gave a Cp and Cpk of 1.5 in 500 prints. The upper and lower spec limits were 60% and 140% of the aperture volume.

Purchasing called to tell her that XLK Company just announced a solder paste with a Cp and Cpk greater than 3, under the same printing conditions that this product required. Needless to say Patty was skeptical. When she looked at the report, she groaned. The data were collected by Mort Bittler. She had seen him give several presentations and he always seemed to misrepresent the data to make his company’s solder paste look better than it was. She was on her way to a team meeting and expected that this new “break through” would be discussed.

As the meeting came to order, the VP of Engineering, Todd Hamilton, spoke.

“I saw this new data from XLK with a printing Cpk = of 3.72, we will use this paste,” Todd commanded.

“Wait a minute,” Patty responded, “the decision on which solder paste to use is with my group.”

“But your group has dropped the ball. How could you not know about this superior paste?” Hamilton challenged.

“We have evaluated their pastes continuously, they have always been second rate,” Patty shot back.

“Well things have changed. Get with it Coleman; this project is too important,” Todd shouted.

Patty was really angry. Technically Todd was her superior, but she found his attitude and words insulting. Using her last name was a bit unfriendly too. “I’ll travel to XLK tomorrow and review their data,” Patty responded, her voice shaking more from anger than anything else. She called Mort Bittler and he was available, so he agreed to meet with her the next day.

As she hung up, Pete showed up at the door.

“Hey kiddo, how’s it going?” Pete asked.

“You were at the meeting, so what do you think? Hamilton impugned all of us,” Patty said flatly.

“Any way I can help?” Pete asked. “Why don’t you go with me to XLK tomorrow, it might be good to have two people check the data.

Fortunately XLK was only 120 miles south of their southern New Hampshire office. Pete had become one of her best friends in the past year. They spoke in Spanish the whole way to XLK to get their skill level up. Patty had also taught Pete some Mandarin, but it was slow going.

After 120 minutes of discussing the PGA Tour vis a vis Tiger Woods, in Spanish, they arrived at XLK. Mort was waiting. Mort was 45 years old, with a thick Boston accent. He came across as being knowledgeable … to someone who wasn’t knowledgeable. After brief pleasantries, Patty asked to see the raw data.

“Patty, I already made the calculations, why do you need to see the raw data?” Mort asked.

“The Professor always told me to ‘look at the raw data,’ ” as often one can glean things that the final calculations don’t show,” Patty answered evenly.

“Well, maybe later. Let me show you how we took the data first,” replied Mort evasively.

Patty and Mort went to the printing lab and Patty noticed that Pete was not with them. After verifying that the printing process was reasonable, Patty asked if she could have a little time with Pete … if she could find him.

Patty and Mort found Pete in the break room. “Pete, let’s pow-wow for a while,” Patty said. Mort said he would go answer some emails and they would meet in 30 minutes.

“Pete, where have you been? You’re not going to embarrass me again are you?” Patty pleaded.

“Me embarrass anyone?” Pete sheepishly replied. “I found the person who took the data, Beth Thompson,” he went on, “and she told me they average Cpks.”

“Not again,” Patty groaned. “We just went through that with a vendor last week. When will they learn that it’s wrong to average Cpks?”

In 30 minutes they went to Mort’s office. All agreed to go lunch. After ordering, Patty asked, “Mort what are your thoughts on averaging Cpks?” Mort seemed defensive, and squirmed a little before he finally he said, “seems OK to me, it’s just like averaging golf scores.”

“What about the nonlinearity of the standard deviation in the Cpk equation?” Patty asked.

Mort was clearly not grasping the issue, so Patty continued, “If you have two sets of data and calculate the Cpk of each and average them, you will not get the same result as if you calculated the Cpk of the data added together. One of the reasons is that the standard deviation is nonlinear. For the same reason it is wrong to add Cpks together.”

Then Patty came right out and asked, “Did you average the Cpks?”

“Yes,” Mort said glumly. “Let’s look at the data when we get back from lunch,” Patty insisted.

When they looked at the data, it showed Patty’s point, four runs, of 100 samples each, had Cpk’s of around 1.2 to 1.3 and one run had a Cpk of 15.56. The average Cpk was 3.73, but if one takes the data together, the Cpk is 1.58.

Patty had calculated the total Cpk on the spot with Minitab (below).

Cp Cpk
Run 1 1.26 1.23
Run 2 1.3 1.3
Run 3 1.39 1.39
Run 4 1.21 1.2
Run 5 15.56 15.54
Average 3.73 3.72
Altogether 1.59 1.58

The correct results, calculated by Patty, are in the last row.

“But the 1.58 still is quite good,” Mort pleaded.

“But the data suggest that run 5 is a fluke; it is clearly not from the same population as runs 1-4. Let’s go out to the lab and run another 100 data points to see if we can reproduce run 5,” Patty insisted.

They ran another 100 and the Cpk was 1.28. On the way over Pete whispered in Patty’s ear that he had more vital intel to share with her on the way home. With the end of the data collection, Patty and Pete were done, so they headed home.

“OK, what is the vital intel you need to share with me? she asked Pete in Spanish.

“While you were collecting data with Mort, I visited Beth again. She told me that Mort had her collect 150 data points on run 5 and he threw out the 50 points furthest from the mean. You were right, run 5 was from another population, a cheating one,” Pete chuckled.

“Well, I guess we will still use our favorite solder paste,” Patty summed up.

Best Wishes,

Dr. Ron

The Productivity Improvement Plan

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Let’s assume you are trying to improve the productivity of your SMT assembly lines. You work at a facility that manufactures high volume products with a high mix. The first aspect of your process that you attack is stencil printing.

You find that your current paste stiffens up when the printing process pauses. So, after a pause, you have to wipe the solder paste off of the board and reprint the board.

Let’s then assume that you replace this paste with a better one that has good response to pause (i.e., you don’t have to reprint a board after a pause). Let’s also assume that this elimination of reprinting boards results in a modest increase in productivity, say 2%. In other words, you are able to process 2% more boards in the same amount of time. No big deal right? Hardly matters?

Wrong! In a typical assembly facility, a 2% increase in productivity results in more than a 6% increase in profits!

You continue working and garner 2% more increase in productivity by balancing your placement machines, improving assist time, and developing a preventive maintenance plan. You have now increased productivity by 8%, but profitability increases by more than 24%!

The calculations that support these conclusions, from ProfitPro, are shown as a graph of profitability increase versus productivity increases. All these calculations support the “Law of Exponential Profits.” This “law” (OK, it was developed by me, so maybe it isn’t a law) states that an incremental (e.g., 2%) increase in productivity results in an exponential (e.g., 6%) increase in profits. The results will vary depending on the assembly facility, but the basic idea is always true.

The bottom line: Investing in productivity always pays.

How is your productivity improvement plan coming?

Cheers,

Dr. Ron

“Fred break, Bob break?” Phil asked.

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Folks,

The “Fred and Bob Breaks” saga continues,

“Fred is the tech responsible for the stencil printer and AOI unit, whereas Bob owns component placement through test,” Chuck started. “The job on line 2 was ready to go, but Fred had the wrong stencil. It typically takes him 30 minutes to find it, so we went on a break. Line 2 is our line.” Chuck finished.

At that the group chanted, “Line 2, Line 2.” The camaraderie and spirit of the team was obvious. A good thing, Phil noted.

“But actually we get more breaks because of that crummy new solder paste,” another fellow, Ivan, chimed in, with a slight Russian accent.

At that everyone groaned. There were murmurs of, “that stuff is crap,” etc.

“Why is that?” Phil asked.

“Well, if the line is down for a few minutes for replenishing the components on the placement machines or some other reason, the paste stiffens up and it takes 30 minutes to knead it or replace it with fresh paste and then to get an acceptable print on the AOI. The new paste is $0.015/gram cheaper than the old one, but it seems like we are losing a lot of time with it.” Chuck replied.

Everyone shook their head in agreement.

“But look on the bright side, Juan wouldn’t be getting his degree if it weren’t for Fred and Bob breaks. And he wouldn’t have Sarah as a girl friend,” a chap named Andy added.

Everyone burst into laughter again, and a few whistled. Sarah turned as red as a rose.

At that point Bob burst into the room and said that line 2 was back up and the group went back to work. As Juan left the room, Sarah introduced him to Phil.

Phil then asked, “What is a Bob break?”

“A ‘Bob Break’ occurs when the line goes down because of a lack of components, or a test or oven issue. It seems as though AXI is quite organized, with the white boards being used for preparing for future jobs. However, both Bob and Fred will fill in the white board and then, when it comes time to run the line, the stencil or components are still missing. They don’t seem to get it that this lack of attention to detail kills productivity,” Sarah summarized.

“Why was Juan in the back of the break room by himself?” Phil asked.

Sarah turned red again and answered, “He got is two-year degree four years ago at Tyler Community College. He now goes to Tech taking 2 or 3 classes at a time for his BS in engineering. Mr. Hermann kindly lets him work flexible shifts to accommodate his studies. We get so many Bob and Fred breaks that he does his homework then.” She almost stopped talking and then she blurted out, “OK, OK, we’re dating.” She looked relieved to get it out in the open.

She then went on to explain how Juan was an operator, but Karl Hermann told him he would become an engineer when he finished his courses this term. Phil chuckled inside to be a witness to this little romance.

He then told Sarah that he wanted to go back to the shop floor, but he made an appointment with her to discuss the uptime numbers that she had measured for the past two weeks.

He continued to observe a few Bob and Fred breaks, and that few lines seemed to be running. On the plus side, all lines seemed to be time balanced between the component placement machines, and the evidence of good Lean Sigma practices like 5S and the 7 Mudas was impressive.

As 4PM approached, Phil headed to his meeting with Sarah. She opened an Excel spreadsheet on her laptop and Phil was shocked to see an uptime of 38.1% prominently displayed. He then looked at the entries and saw that many of the 1s (a “1” indicating that a line was up when Sarah checked it) where colored, some blue, some red, and a few green. All of these colored 1s also had an Excel comment flag. Phil could see it coming.

“Why the colored 1s?” he asked Sarah.

“Fred and Bob came to me all during the days I was recording the data. I would score a “0” (the line is not running) and they would say that I should score a “1” because they couldn’t find the stencil or components, etc, etc. When they told me to do this, I would score a 1, but if it was a Fred break, it was a blue 1, a Bob break, a red 1 and something else would a green 1. Fred and Bob argued that many times when I scored a 0, that it wasn’t normal it was just a fluke. So they insisted I put a 1 in, I did but I color coded them. A fluke, right, look at the colored 1s, everything is a fluke then!” she finished in disgust.

Sarah was skilled in Excel however, and she wrote a formula in one cell that would only count the black (non-colored) 1s. This cell showed that the uptime was only 9.9%.

Phil quit for the day and went to his hotel. The next day he planned to observe the line some more and develop his suggested action plan.

On the third day he gave a summary to Karl Hermann, Fred, Bob, some of the managers, and most of the engineers. Phil started off by discussing uptime. Fred and Bob had been to some SMTA and IPC meetings and knew that 30-35% uptime was quite good, so they were anticipating praise to be heaped on them by Phil.

Phil stared, “The uptime on the four lines that AXI has is…….”

Fred and Bob were waiting for the good news of 38.1%.

Will Fred and Bob be happy with the uptime numbers?  Stay tuned.

Cheers,

Dr. Ron

‘The Professor,’ Compiled

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Folks,

A compilation of my blog posts, titled The Adventures Of Patty And The Professor, is now available in soft and hard copies. The advantage of the soft copy is that the hyper links can be used. However, a hard copy is nice to carry around. The hard copy is over 60 pages and the format is a little larger than a paperback’s. If you are interested in either, send me a note at [email protected] and I will send you either one. If you want a hard copy, send your land address.

Several people have asked why I am extolling scientific and industrial principles and advice in an allegorical format. Some advise me to just say “improve your uptime” or “a cheaper solder paste isn’t always cheaper, especially if it reduces throughput.”

Well, I am following after Goldratt. In The Goal, he takes essentially the entire book to tell a story about the theory of constraints. Because it is a story, with people and their foibles, it is often easier for readers to relate to, and especially remember, than if he were to simply say, “Do this, do that, to improve your process.”

Goldratt’s book, and style, created a new expression, “Finding the Herbie (constraint) in a process.”  Check up on Herbie to see what this means.

Bottom line, there are many ways to learn. Using multiple ways helps us find the BEST way. When we find the best way, everyone wins. I hope my work can help you find the BEST way to improve your process, and your profitability. Tell  me where to ship YOUR book.

Cheers,

Dr. Ron

On Pb-Free Reliability and its Doubters

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I was at SMTAI (Surface Mount Technology Association International) in late September. As mentioned, I chaired a session on Alternative Alloys. At this session, Greg Henshall presented a paper on the Low Silver BGA Sphere Metallurgy Project. This paper was a collaborative effort of six companies. In addition, Richard Coyle presented an overview of the work of three companies titled “The Effect of Silver Content on the Solder Joint Reliability of a Pb-free PBGA Package.” Both projects evaluated lead-free thermal cycle reliability as a function of silver content and compared the results to SnPb reliability.

Both papers concluded that as far as thermal cycle reliability is concerned

SnPb < SAC105 < SAC305 < SAC405

Coyle’s paper summed it best:

Each of the SAC alloys outperformed the SnPb eutectic alloy in every test, including the long, 60 min. dwell time test. This tends to diminish the argument that SAC is less reliable than SnPb. (See Coyle’s figure. Data curves to the right are more reliable.)

Henshall’s paper also showed that the addition of dopants, to improve shock resistance, in SAC105 does not reduce thermal cycle life.

So, it appears, at this time, that, from a thermal cycle and drop shock perspective, it is looking more and more like SAC-based solders out perform SnPb solders in these two reliability arenas.

At the end of the session a noted lead-free curmudgeon came over to introduce himself.  We have had a jovial disagreement on several blogs, etc., in the past re: lead-free status and issues, but had not met in person. I should mention that this person is a college graduate, a former technical leader at several influential technological companies, and he owns a PE license. I asked him what he now thought about lead-free reliability after hearing the talks. He claimed that he is a little less likely to think that Pbfree reliability is a disaster. He still refuses to purchase lead-free products. He buys old units (pre-2006) on eBay.

I mentioned that over $2 trillion of electronics has been placed in the field since 2006 with no unusual reliability issues. I then went on to say that a RoHS-compliant product is much more likely to fail due to a non-RoHS related issue. He did not disagree. So then I asked him why he won’t use RoHS compliant electronics. His answer: “I just don’t trust them.”

Cheers,

Dr. Ron

Driven by Data

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Patty was wrapping up a few things before lunch. Her company, ACME, had just received a large order for the new Druid cellphone and she had responsibility to develop a scale up plan to assemble 3 million units a month.

ACME had received this contract by beating two assemblers from China. This win only was possible because of the work her team had done on the very high uptime lines. This high uptime allowed ACME to come in with a competitive quote that was more attractive than the Chinese companies. With the added advantage of not having to ship the Druids from China, and fewer IP (intellectual property) concerns, ACME got the contract. It was a major feather in her cap. But now she had to deliver.

The customer even had given her a new Druid phone. It was very impressive, but she wondered why they named it after such mystic people. Oh well, she thought, this just confirmed that she should not be in marketing.

As she was wrapping up, she checked her email. She saw an article on one of the online trade journals: Netbook Sales Are Crashing! Quick! Blame The iPad, Not The Lousy Netbooks! . She was curious, so she read it. The article began:

Well what do you know? Netbook growth is so low right now that in a recent report by NPD, Morgan Stanley Research lists last month’s growth as a negative number. That’s right, people are apparently selling the notebooks back or something. (Not really, but no one is buying netbooks right now).

Looking at the graph, she thought a more appropriate title would have been: “Despite launch of the iPad, netbook sales reach all-time high in July.” After finishing the brief article, she went off to lunch.

Patty was glad that, even after her promotion, her lunch friends still felt comfortable with her as part of their daily friendly ritual. As she approached the lunch table she heard Phil and Rob arguing.

“Rob, I’m telling you, I read it on line, Netbook sales have crashed, they have essentially gone to nothing almost overnight,” shouted Phil.

“But our plants in China are making just as many as they were in July,” Rob shot back. “I should know, its part of my job,” he finished.

“Patty, they are fighting again. Can you break them up?” Jan Curtis teasingly implored.

“Hey guys, what’s going on?” Patty asked.

“It’s your hubby again, he doesn’t recognize that an important part of his business is gone. I saw the graph,” Phil answered.

“I saw it too,” said Patty, “And, if you study it, I think the author was mistaken or misleading.”

Patty brought the article up on her new Druid phone. The resolution and size of the screen was so good that it was easy for everyone to read the graph and the article. She handed it to Phil.

“Phil, look at it closely and see if you don’t think the author made an error,” Patty said.

Phil looked at it for a few seconds and then became a little red in the face. He handed the Druid to Rob.

“Yikes, I’m embarrassed. It was the growth rate that tanked. The absolute sales only went down 4% in August. July was a record month,” groaned Phil.

The cell phone got passed around the table and everyone read the article.

Pete Wilkins summed it up, “Netbook sales may be down a little in August, but no data support their sales crashing. This might become the case in the future, but we can’t tell from the data provided.”

Epilogue: As Patty walked back to her office and settled into her chair, she once again looked at the article on her Druid.  What she saw caused here to just about drop the Druid.

The graph did not say “Netbook,” it said “Notebook.”

“Double yikes!” she thought. “The author not only got the numbers wrong, but got the product wrong.”  She followed the links to the source article and saw that the entire article was about notebooks, not netbooks!

Au. note: We should be data-driven in the decisions we make at work, at home and in our lives. Few things are as important. So I feel that it is helpful to point out the misleading nature of articles like the one referenced above.
Cheers,
Dr. Ron