Witchhazel

This is a guest post by Dave! Go check out his food blog.

So, I have a job interview for the position of project estimator. A great secret is that although I am currently a project estimator, I have no clue how to estimate projects. Luckily, I have discovered the math which will solve my problems!

Let’s say my project is eating a cupcake.

…

Okay, let’s say I am eating a cupcake, and have decided to call this a project. Not that some horrible project-monster is ransacking my pantry.

I take the best possible, worst possible, and expected time to eat this cakey delight. I run them through a formula, run them through a second formula, and end up with an estimate and a variable.

Keep with me.

Now, if I go with just the estimate, there is a 50% chance I will successfully eat the cupcake in 2 minutes.

Tracy: “Well of course it’s fifty percent! You either eat it, or you don’t!”

Me: “…”

Tracy: “What?”

Me: “Probability doesn’t work that way. 50% doesn’t mean that it is just as likely something will, or will not be true. For example, the cat may be a cat, or he may be a dinosaur. That does not mean there’s a 50% chance he’s a cat, or a 50% chance he’s not a cat.”

Tracy: “Or there’s a 50% chance he’s a dinosaur, or a 50% chance he’s not a dinosaur!”

Me: “… So, let’s say best case is I finish the cupcake in two minutes. Maybe some stuff happens to delay me, so it’s more likely this will take five minutes. However, if I am mauled by a dinosaur, it may take me up to eight minutes to eat this cupcake. I plug that in a formula, get my variable, and then I can add the variable to my estimate. If I add my variable of one minute to my estimate of 5.5 minutes I now have a 75% chance to finish the cupcake in the estimated time.”

Tracy: “Right! Because as time goes on, the dinosaur is more likely to attack you!”

Me: “…”

Tracy: “Or the chance increases that the cat is a dinosaur, thus delaying you from enjoying your cupcake.”

Me: “And if I triple the variable and add it to the estimate, my chance goes up to 99.5%. So there’s a 99.5% chance that I will finish the cupcake in around seven and a half minutes.”

Tracy: “But you stopped eating the cupcake for ten minutes to write this guest post! Now the cat is sure to be a dinosaur.”