HP Printer Pokayoke Example

This is a new HP C7250 printer we purchased a few weeks ago. It’s quite the desktop machine, with built in copier-scanner. Setting up the wireless was a skosh frustrating but all in all a great product. While installing the ink cartridges we came across a good example of pokayoke: the lean principle of building quality into a process through mistake-proofing.

The different color ink cartridges are, of course, color-coded. But they each also have a unique shape, presumably for people who are colorblind. That is a very nice touch, customer-focused.


Here we are trying to insert the cartridge upside down and backwards. No dice. That’s the least we can ask for in terms of designed-in quality for modern electronics, we might say, but there’s more.

The intuitively obvious matching of color and shape gets you close…

…but the positive match of the knob of the cradle ensures that there is only one correct way to install this ink cartridge…

…and sensors alerted us to the fact that we left out the red ink cartridge (just testing). But what if I wanted to play a trick? Red is the new pink! Let’s switch the in colors and see what happens. Not so fast, true pokayoke protect against more than human error, they positively prevent intentional failures also.

Nicely done, Hewlett and Packard, very nicely done.