A coworker introduced me to the concept of Poka-yoke in the last year or so, and I’ve been obsessed with it ever since. The tl;dr version of Poka-yoke is that processes should aim to implement control poka-yokes that prevent incorrect behaviour, and warning poka-yokes that indicate incorrect behaviour. So here are some stories about poka-yokes in my personal life…
Years ago, I was lived in a house in which each door had both a handle lock and a deadbolt. Each day before exiting the house, I locked the handle, which was only possible from the inside of the house. I would then back out of the house and use the hand in which I held my house key to pull the door shut. One day as I shut the door, I accidentally dropped the key beneath the door’s path, and closed the door locking myself outside. When I bought my first house, I had all of its doors changed to only use deadbolts. These deadbolt-only doors operate as control poka-yokes, ensuring that I need to be on the outside of the door and in possession of a key to be able to lock the door. Simple, and over the years it has saved me more than once.
I used to take a padlock with me to use on lockers at the gym, keeping the key in the pocket of my gym shorts. One day, I forgot the key inside the locker. Thankfully the staff didn’t need any convincing to lend me their bolt cutters. Afterward I bought a combination lock for which I could set a memorable combination, and I keep it locked when not in use. Keeping it locked is both a control and a warning poka-yoke. If I can’t unlock it (control), I don’t remember the combination and shouldn’t be using it. If it takes me several tries to unlock it (warning), I don’t reliably remember the combination and shouldn’t be using it.
Finally, I’ve bought myself a pill container that has both AM and PM compartments for each day of the week. Prior to having this pill container, I only used Google Reminders to tell me when I should be taking pills. While that worked sometimes, I tended to silence reminders and neglect to address them later. To augment Google Reminders, I leave the pill container in a prominent location. The pills being organized beforehand prevents me (control) from taking duplicate dosages. The pills being visible indicates (warning) when I have failed to take a dose.
These are some of the minor changes I’ve made to my life that help protect me against myself. Hopefully they give you some ideas you can use, or at least give some background on why I maintain that Rule #1 is “Mak is not to be trusted.”