High speed, high variety, high volume: Pick two

You’re driving yourself crazy. As a customer, you and everyone else are demanding more and more personalized products. As a producer, this explosion of SKUs to satisfy every niche of the marketplace is driving you crazy. It’s not going to get any better so you might as well get used to it.  Ultimately we will likely wind up with most products produced one at a time, individualized for each end user.

Maybe you think  the answer is higher speed lines. After all, higher speeds will mean you can produce more, right?

Wrong.

Higher speeds just let you fail faster. That’s not the goal, is it? When you shut a 100bpm line down for an hour for changeover, that’s 6,000 products you don’t produce. Shut down a 250bpm line down 2 hours and you’ve lost 30,000 products.

To minimize this loss, you may decide to increase the lot size but that’s not the answer. Bigger lots mean reduced responsiveness and higher inventory costs. You just can’t win.

Faster lines and bigger lot sizes are the problem, not the solution.

If you need to run a high variable mix of products or if your crystal ball seems to get cloudier each day, consider multiple low speed lines instead of a single high speed line.

Multiple low speed lines aren’t just a little cheaper to buy, they are a lot cheaper. They’re also a lot simpler. The rule of thumb is about 4 to 1: Double the line speed and the equipment cost quadruples. Double the speed and equipment complexity quadruples.

Instead of 1 line running 250ppm, consider 2, each running 100ppm. Even better, consider 3 lines, 100ppm each but only crew 2 of them at a time. The third line can be in changeover while the others are running. When you finish one lot, move the crew to the other line for a new product. This gives you non-stop production.

You don’t need speed, you need product on the truck. Multiple low speed lines just may be the best way to get there.