Explaining Technical Debt, with Tea
Technical Debt can be a difficult concept for people to understand, so lets try a metaphor.
Let us imagine we have identified a user need like this:
As a the a person alone in a house
I need a cup of tea just how I like it
so that I benefit from the unique properties of the oriental infusion and feel sated.
You are probably imagining what you need to do to make your perfect cup of tea - or coffee if that's your thing, steps like: go to the kitchen, fill the kettle and put it on, get the milk out of the fridge, and so on. This is our Value Demand– the work done to enable the value of making a cup of tea.
Pretty straight forward so far, right? But hang on, there's a catch!
You're not making the cup of tea in your beautiful tidy and organised kitchen, oh no, this is a kitchen in a student house. Occupied by student athletes, and it gets worse, they're rugby players.
This kitchen is an absolute disgrace, it's a health hazard. No one has cleaned this kitchen since they moved in. There is nothing remotely edible kept in this kitchen, instead it is a collection area for used takeaway cartons and pizza boxes.
Now lets think about what you have to do to make your cup of tea. I’m guessing it now involves going to the shops to buy teabags, milk, sugar, a mug, and if you’re unlucky a kettle and some bottled water too. It might involve buying and using a lot of cleaning products before you get anywhere near finding the kettle much less turning it on.
This is your Failure Demand. This is work you have to do that has nothing to do with the value you are trying to release. This is work you shouldn’t have to do to make a cup of tea, but now you have the technical debt, you have to pay off on the Failure Demand in order to be able to deliver any of your Value Demand.
This is the technical debt problem. If you tidy up your environment as you go, then making tea is a simple thing and most of the effort you spend is in Value Demand of making tea. If you don’t tidy as you go, the environment builds up detritus and debris, and eventually even doing the simplest thing involves servicing a lot of Failure Demand – cleaning other rubbish out of the way to enable any value work to flow through the kitchen.
Whenever you are doing some knowledge work, I invite you to ask yourself, "Have I left the kitchen in a reasonable state behind me? Is it at the very least no worse than before I started?" If not, what would your mum tell you to do about it? Go on, get back in that kitchen, you know what you need to do.