Dijkstra on System Design

This paper by Dijkstra was linked from a discussion on ArsTechnica about system design. It’s amazing that many of his high-level points remain true today, despite being published in 1968 – I’ve picked out a few below:


Production speed is severely degraded if one works with half time people, who have other obligations as well. This is as least a factor of four, probably it is worse. The people themselves lose time and energy in switching over, the group as a whole loses decision speed as discussions, when needed, have often to be postponed until all people concerned are available.

Star developers:

The intellectual level needed for system design is in general grossly underestimated. I am more than ever convinced that this type of work is just difficult and that every effort to do it with other than the best people is doomed to either failure or moderate success at enormous expenses.

Unit testing:

It seems the designer’s responsibility to construct his mechanism in such a way —i.e. so highly structured— that at each stage of the testing procedure the number of relevant test cases is so small that he can try them all and that what is being tested is so perspicuous that it is clear that he has not overlooked a situation.

I’d add to the list that it’s vital to spread knowledge within a team to maintain productivity and avoid one person being silo’d to a specialist skill and becoming a bottle neck. Instead, find out how to pull the source code out of the repository, how to build and test it – and start making small changes yourself as a learning exercise.

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Filed under Programming, Soft skills

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