Category Archives: hands-on

Working Effectively with a Performance-Testing Bottleneck

Not long ago, a software performance architect brought to my attention that she and her colleague (the performance-testing team) were overloaded with performance-testing requests from product teams. The performance testers wondered if they needed to change their mini-team’s process to … Continue reading

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Shew-Ha-Ri: a Three-Level Model for Dealing with Variation

Continuing the statistical theme of the last two posts, but trying to close it at the same time. I observe three different levels of dealing with the same problem: look at a data set of some metric and tell whether … Continue reading

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On the Practically Useful Properties of the Weibull Distribution

In my previous post, I referred to the insight (created by experts who have analyzed lots of real-world software and IT project data) that lead times in such projects often have the Weibull distribution. I also explained a bit what … Continue reading

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How to Match to Weibull Distribution in Excel

UPDATE: The contents of this post are still valid, but there is a new, complementary post: How to Match to Weibull Distribution without Excel. Warning: this is a very technical, hands-on post. It turns out Weibull distribution is quite common … Continue reading

Posted in hands-on | 24 Comments

Scrum, Kanban and Unplanned Work

A colleague sent a link to an article to a group of colleagues and ask for a comment. The article was published in one of the popular online IT magazines. My goal here is not to criticize or fix this … Continue reading

Posted in hands-on | 7 Comments

T-Shirts, Rabbits, Lizards and Sizing Software Features

I was at Agile Open Toronto last weekend, which included a no-estimates session. That session and the open-space conference itself deserve separate blog posts, but for now I want to cover just set of concerns that relates to sizing and … Continue reading

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Scrum Commitments, Little’s Law, and Variability

I have recently had a discussion with a Scrum Master whose team was struggling quite a bit, completing exactly zero stories for two straight iterations. This problem is often framed as overcommitment – how can we make them team commit … Continue reading

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It’s Not About Estimation, It’s About Risk

The Pragmatic Bookshelf has recently published an article by Ron Jeffries, Estimation is Evil. I didn’t enjoy it for a number of reasons. The word evil turns the article into a religious argument and sensationalizes it needlessly. I would have … Continue reading

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Commitment, Forecast and the Toyota Kata

My last post, On WIP Limits, Velocity and Variability, explained how variability can combine with certain habits and the ignorance of pull systems to create a situation where a Scrum team repeatedly delivers roughly half of their user stories committed … Continue reading

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On WIP Limits, Velocity and Variability

A prominent agilist posted a question on Twitter that lead to a long discussion: “Can Scrum teams use velocity as the WIP limit for a sprint? Will it take them closer to pull-based planning?” Several replies quickly followed from many … Continue reading

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