Indium Blog

Maximizing Uptime in Electronics Assembly

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  • Dr. Ronald C. Lasky: Phil, you and I have been in what, got to be, hundreds of factories over the years, right? Most of the time, we ask people in the factories, what is their uptime. What percentage of the time is their lines running, and I think they usually tell us something like 85%, right?
    Phil Zarrow: Right.
    Dr. Ronald C. Lasky: What do you think reality is?
    Phil Zarrow: Probably if they're getting anywhere close to 30%, they're doing alright.
    Dr. Ronald C. Lasky: That's my sense, too. If you're doing 30%, that's about as good as it gets. That surprises people. What are some of the reasons why people aren't getting better uptime?
    Phil Zarrow: First of all, I think one of the things is they're basing that 85% ... Where did that number come from? Essentially, that's machine availability time.
    Dr. Ronald C. Lasky: Yeah. The machines are available.
    Phil Zarrow: The machines are available and if they were running continuous and nonstop, in the ideal world with perpetual motion and everything else, then they might get close to that. That's a nice figure that the machine manufacturers ... And yes I would expect machines to have an availability time of 85% to 90%.
    Dr. Ronald C. Lasky: Right.
    Phil Zarrow: Reality is, there's lots of interruptions and that doesn't make that a continuous flow process.
    Dr. Ronald C. Lasky: What do you think's the biggest interruption?
    Phil Zarrow: I think one of the biggest is setups.
    Dr. Ronald C. Lasky: Setups. Yeah. Setups take a lot of time. Going from one job to another.
    Phil Zarrow: Right, and of course, in a high-mix situation it becomes even more profound.
    Dr. Ronald C. Lasky: I think replenishing the feeders on the pick-and-place machines. They're constantly doing that.
    Phil Zarrow: Right.
    Dr. Ronald C. Lasky: That takes a lot of time. What are some of the other ones?
    Phil Zarrow: We look at the printer, certainly replenishing solder paste. If it's not done automatically and then of course the solder paste response-to-pause.
    Dr. Ronald C. Lasky: That's something a lot of people don't think about. That's a really important solder paste metric, response-to-pause, because if you have to stop the line for a few minutes and this happens probably several times a day, if that solder paste stiffens up, then you've got to print a board or two that you just wipe clean because the first couple of prints won't be good because it has poor response-to-pause. That's a critical solder paste metric I think that some people don't think about.
    Phil Zarrow: Right. Then of course, we have the human factors. If the machines are running automatically and we've seen lines where, actually I recall seeing a line a couple years ago that were running 50% true uptime because it was a highly automatic line, high volume, almost no mix and they got it, but you have the human factor, things like changeover and let's talk about human other things. Let's talk about lunch.
    Dr. Ronald C. Lasky: You remember, probably you've heard me talk about this place where they claim they only had a half an hour for lunch, but yet the operators wanted to make sure that they didn't miss lunch so they turned the line off about 20 minutes early. Then they went to the half an hour lunch, which was really 40 minutes, and then they came back and it took them a half an hour to get the line going again. I measured that their line was down for 90 minutes every lunch hour.
    Phil Zarrow: Yep. Invisible time.
    Dr. Ronald C. Lasky: What's a way to address this problem of more uptime?
    Phil Zarrow: First of all, I think you have to be conscious of it and that's from management on down and for lack of a better word, you have to have a passion for it.
    Dr. Ronald C. Lasky: I once remember–I was at a facility where when the line was down, operators would send a note to their boss and he would send a note to his boss, and this happened a couple of times. I was there for a week and it was nine in the morning the line would be down. I'd come back at two in the afternoon and the line's still down. They had an escalation policy but it stopped at some boss that was so busy he wasn't checking his email. We told them, if the line is down for more than 45 minutes, the site general manager needs to know, because it's that important. Because, as you and I have discussed, it's only thing that is making money for your company—is a line running. It's like a printing press for paper money. If the press isn't running, you're not producing any money.
    Phil Zarrow: That's one of my favorite analogies that you've done. Yeah. Exactly.
    Dr. Ronald C. Lasky: I think one of the things too is, we've mentioned setups, we've mentioned replenishing times for the feeders, we've mentioned replenishing the solder paste and worried about response-to-pause, but I think it's so important for your line to be running. That's what's making money that really the responsible people at a company, the process engineers and the managers should have a continuous improvement plan where they're addressing and measuring each of these metrics to make sure that they have a good uptime. And, I think you and I agree on this, if you really pay attention to it, it is possible to approach 50% uptime. I've covered these topics in my book, The Adventures of Patty and the Professor, which can be found at If anybody has any questions about this topic, please contact me at
    Phil, this has been really a great discussion. Let's do it again sometime.
    Phil Zarrow: Thank you, Ron.