I was asked the other evening what I considered to be the secret of successful projects, and because I’d had a couple of drinks I happily provided an answer: Incremental delivery. And even now the hangover’s worn off I still think that’s not a bad response.

If you deliver small, valuable units continually then your project managers can do their job properly. They can assess progress early, and escalate or take action accordingly. They can steer on a much more fine-grained level. In fact, they can steer the project exactly like one would steer a car: continual tiny adjustments of the wheel in response to continual feedback from the road and the vehicle. If deliverables were only assessed quarterly, say, then the steering would be wild and destabilising, if it was possible at all.

Incremental delivery doesn’t ensure a successful project, of course, but it does give you a much better chance of making it happen.

Almost as a proof by counterexample I was interested to hear a couple of days later about the failure of G4S to provide the promised 10,000 security staff for the London 2012 Olympic Games. G4S’s CEO explained the failure as follows:

So, basically, you work through that process of numbers [of getting 100,000 applications, resulting in 50,000 interviews, etc] and as they were getting ready for deployment over a period of time, it’s only when you get closer and closer to the games that you realise that the number isn’t as high as you expect.

The deliverables (qualified security staff) did not get output from the recruitment system incrementally — they arrived only late in the process. And so by the time it was apparent the numbers weren’t going to stack up it was too late to do anything about it. They might have had great project managers, but they didn’t have a chance to manage that very significant problem.

Incremental delivery allows effective project management.