teaching

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Rolling Rocks Downhill

It’s almost a year since I posted a glowing review of “The Phoenix Project” – a business novel, following in the footsteps of Goldratt’s “The Goal”, about continuous delivery. If you haven’t yet read it, then I’m going to recommend that you hold fire, and read “Rolling Rocks Downhill” by Clarke Ching instead.

I should point out that Clarke is a personal friend of mine and a fellow resident of Edinburgh, so I may be a little biased. But I don’t think that this is why I feel this way – it’s just that Clarke’s book feels more real. Both “Rolling rocks….” and “Phoenix…” have a common ancestor – “The Goal”; both apply the Theory of Constraints to an IT environment; and both lead eventually to triumph for the team and the lead protagonist.

There’s something decidedly european about Clarke’s book, which makes me feel more comfortable. The reactions of the characters were less cheesy and I really felt like people I know would behave in the manner described. (Maybe that’s because these characters really are based upon people I know ;)) There really are cultural differences between Europe and North America, and this book throws them into sharp relief. The inclusion of the familiar problems caused by repeated acquisitions and a distributed organisation only added to the feeling that this story actually described the real world, rather than an imaginary universe powered by wishful thinking. The only time that my patience wore thin was around the interventions of the “flowmaster”, Rob Lally, who is ironically a real person.

A truly useful addition in Clarke’s novel is the description of the Evaporating Cloud diagram, which (I now know) is one of the 6 thinking processes from the theory of constraints. For […]

By |February 12th, 2015|Agile, Continuous Delivery, Practices|1 Comment

Reduce, Reuse, Recycle

From http://kids.niehs.nih.gov/explore/reduce/:
Three great ways YOU can eliminate waste and protect your environment!

Waste, and how we choose to handle it, affects our world’s environment—that’s YOUR environment. The environment is everything around you including the air, water, land, plants, and man-made things. And since by now you probably know that you need a healthy environment for your own health and happiness, you can understand why effective waste management is so important to YOU and everyone else. The waste we create has to be carefully controlled to be sure that it does not harm your environment and your health.
What exactly is “waste?”
Here’s a list (not exhaustive, by any means):

Code that doesn’t get used
Log entries that give no information
Comments that echo the code
Tests that you don’t understand
Continuous integration builds that aren’t consistently green
Estimates that you aren’t confident in

How can you help?
You can help by learning about and practicing the three R’s of waste management: Reduce, reuse, and recycle!

Reduce – do less. Don’t do something because that’s what you’ve always done. Do it because it adds value; because it helps you or a colleague or a customer; because it’s worth it.
Reuse – repetition kills. Maybe not today or tomorrow, but eventually. Death by a thousand cuts. Eliminate pointless repetition,  and go DRY (Don’t Repeat Yourself) for January. You’ll enjoy it so much, you’ll never go back.
Recycle – is there nothing to salvage? Really? When you find yourself building that same widget from scratch again, ask yourself “why didn’t I recycle the last version?” Was it too many implicit dependencies? Or was the granularity of your components not fine enough? Try building cohesive, decoupled components. Practice doing it – it gets easier.

By |January 12th, 2015|Agile, Cyber-Dojo, Musings, Practices|0 Comments

Teaching TDD (TTDD)

There has been a flurry of discussion about how to teach TDD, sparked off by a recent post from Justin Searls. In it he lists a number of failures that range from “Encouraging costly Extract refactors” to “Making a mess with mocks” all of which distract attention from the concept that “TDD’s primary benefit is to improve the design of our code”. He concludes by suggesting that once you have written a failing test, rather than get-to-green in the simplest way possible you should “intentionally defer writing any implementation logic! Instead, break down the problem by dreaming up all of the objects you wish you had at your disposal”. In essence, design the elements of the solution while the first test is still red.

It’s an interesting post that raises a number of issues, but for me its value lies chiefly in opening the subject up for debate. The introduction is particularly pertinent – just setting a class a bundle of katas to do does not, of itself, encourage learning. The pains experienced while doing the exercise need to be teased out, discussed and have alternative approaches described. If you don’t hear the penny drop, then it hasn’t dropped.

Pitching in with characteristic vigour and brimstone came Uncle Bob with a robust rebuttal containing both heat and light (though some have been put off by the heat and never got to the light). Bob makes some good points regarding the fallacy of writing tests around extracted classes, the tool support for extract refactoring and the central place of refactoring in the Red-Green-Refactor cycle.

By the conclusion, however, Bob has switched tack. He states that while refactorings are cheap within architectural boundaries, they are expensive across them. Whether he’s right or wrong […]

By |February 4th, 2014|Practices, TDD, Unit testing|2 Comments