Category Archives: Estimation

Student’s t-statistic

Introduction In 1908, a guy at Guinness found a way to measure which types of barley produced the best beer-brewing yields: he called it the “t-statistic”. However, because Guinness was paranoid about giving away trade secrets, he had to publish his ideas under the pseudonym “Student”. Although we now know his name was William Sealy… Read More »

We’ve been doing it all wrong!

I can hear myself saying it now: “If you count up the number of work items in each column, and keep a record of each item’s start and end date, then you can create a CFD [Cumulative Flow Diagram], control chart and histogram”. Apparently I was wrong. Apparently nearly all of us are doing it… Read More »

Don’t forget to add in the conversation

Story, Epic or even Saga, what is the difference? David Lowe’s post from last year gives a good description of each. However, in my opinion, there is not much difference. A story, epic or saga all narrate the type of user, the need of the user, and the value returned by fulfilling that need. The… Read More »

Little’s Law and CFDs

How much information can a triangle give you? Well, if it’s on a CFD (‘Cumulative Flow Diagram’), then it appears to be quite a lot. After sitting in a presentation recently, someone came up to me to ask how changes in WIP, Cycle Time and Delivery Rate alter the shape of a CFD. Specifically, how the… Read More »

The Cobra Effect

I have worked in lots of organisations where ‘management’ has tried to measure and monitor development teams with the aim of seeing how the teams are performing and then using that information to drive through improvements in performance. This desire to measure and control things can often have some unintended consequences. In the best-case scenario,… Read More »