Why are you estimating?

In a previous job I had a quote stuck up behind my desk that I would point to when a manager asked me for an estimate.  I cant remember the exact wording but the gist of it was something like:
Before asking for an estimate first ask yourself what decisions the estimate will be informing. 
I loved this quote because it points at one of the biggest problems that I think the software development industry has with estimates, and one of the reasons that they are, so often, so wrong.

Too often we estimate work in a vacuum without adequate knowledge as to why the estimate is being asked for, or how it's going to be used. 

There are many different, and valid reasons to estimate work, and different situations call for different techniques. For some of these cases the trivariate estimate method that I suggested in a previous blog is a great answer that will provide low level detail about the estimate and allow good decisions to be made, for other cases it is a massive waste of time. Similar ideas can be drawn for the story points, t-shirt sizes or the no estimates movement.

Each type of estimate is suited to a situation, and you can never know what is needed unless you can understand why you're being asked for the estimate and what decisions that estimate is informing.

Comments

Post a Comment

Popular posts from this blog

Solving `Empty reply from server` in DotNet Core

tldr; If you’re getting  curl: (52) Empty reply from server  check that you’ve configured Kestrel correctly. Long version I’ve started playing with Dotnet Core and Docker and have had a few issues getting started. I’ve had a little bit of experience with Docker, though only a little. I’ve worked with DotNet previously but never with Core. Environment The setup I’m using is a Windows laptop running Vagrant. Via Vagrant I’m running an Ubuntu Virtual Machine with the Docker run time installed. Feels a litle like inception. Key Problem The key problem that I’ve had getting started was having my Docker container not responding correctly to my curl commands. I get this: curl: (56) Recv failure: Connection reset by peer curl: (52) Empty reply from server Given that I’m not all that familliar with Docker or Dotnet Core I decided to remove one of the variables and set up a simple Express app in a different docker container. This validated that the commmand I was using to run
Read more

Testing functions that use local storage with Jest

Testing functions that use the browsers local storage API seems easy when you know how. Here's a quick run down on how to mock it out with Jest if, like me, you're not familiar with how to test it. In the end it's very little code. Consider the following TypeScript code. import { get, save, key } from "./storage"; describe(save, () => { let setItem: jest.Mock; beforeEach(() => { setItem = jest.fn(); Storage.prototype.setItem = setItem; }); it("should call set item with predefined key and json object", () => { const valueToStore = { value: "toStore" }; save(valueToStore); expect(setItem).toHaveBeenCalledWith(key, JSON.stringify(valueToStore)); }); }); The key lines are in the beforeEach call where the setItem function of the Storage prototype is assigned to an instance of jest.fn() . This allows us to make assertions on what is passed to the local storage setItem API.
Read more

Building a verify JWT function in TypeScript

# Verifying an RS232 signed JWT JSON Web Tokens (JWT) are used as a way to verify the identity of the caller of an API. **The best way to verify a JWT is to use a verification library.** I wanted to have a look at some of what those libraries are doing under the hood by putting together a function that will return if a given token is valid. In this blog I'll go through what I have done to get a validation function working. To simplify things assume: - That the signing algorithm is RS232 all others are considered invalid. - That the public keys are available on a JWKS url provided to the function eg [https://klee-test.au.auth0.com/.well-known/jwks.json](https://klee-test.au.auth0.com/.well-known/jwks.json) - I only want to know if the token was signed by a key available at the above url. I wont be checking if the token has expired, if the scopes or other claims are valid. # Break up the token A JWT is made up to 3 parts. The first thing to do in validating the token is to brea
Read more