Do you bristle when people bring up work in progress (WIP) limits? Work in progress limits are a defining feature of Kanban. Without WIP, you don’t have Kanban. It’s that simple.
But what is a WIP limit, and why is a WIP limit important?
A WIP limit is simply a cap on how many tasks can be in progress at once. This helps teams focus and finish before starting something new.
When I was growing up, we’d go camping most of the summer. It was a bit of work when we arrived at the campsite, sometimes late, but it was fun. We’d arrive at a bare campsite with nothing but a fire pit and maybe a picnic table and have to build our home away from home before we could rest.
That’s a project right there: arriving past nightfall to an empty campsite in the forest, surrounded by trees. After sunset, it’s so dark there’s no difference whether your eyes are open or closed.
You might have kids with you who have been cooped up in the car for hours. You want to move quickly, because the adults are also tired and tempers are shorter. While the kids are bouncing around, when they run out of gas they will be down for the count. You’ve got at least one tent to set up before you can rest.
Does it make sense for one person to be lighting the lantern while another is trying to find a spot for the tent and another is cleaning the entire campsite of rocks and sticks just in case the tent is going to go there, while a fourth tries to get the tent out of the vehicle in the dark?
Of course not! Like any good team, you shouldn’t start every task at once. Focus instead on the most critical work first: lighting the lantern. In this case, darkness is a bottleneck. Once you can see, flow improves.
Once the lantern is lit, you can find a site for the tent, clean it of debris, get the tent out of the vehicle, and then set up the tent – in that order, one task at a time. So your tent preparation column has a WIP of 1, and everyone focuses on that to get it done.
That’s the power of a WIP limit. It forces you to focus on the next essential step before starting another task.
Once the tent is up, you can have a higher WIP as more people do more tasks at the same time: One person is in charge of unloading the vehicle, while another is assigned to the air mattresses, both carrying them into the tent and inflating them there. Another person begins moving the sleeping bags into the tent.
Of course, WIP gets adjusted on the fly as needed. Maybe in the chaos of setup there’s not enough space in the tent to inflate the air mattresses and haul in both the sleeping bags and the luggage. Maybe there is a leak in one of the air mattresses and it takes two people to find it, so the person bringing things into the tent stops to help feel and listen for the leak.
In project work, just like at the campsite, setting and respecting WIP limits keeps everyone focused, aligned, and ready to enjoy the results together. With everyone working together in flow, you can get your home away from home set up in record time.
You might even have time to toast marshmallows before bed.