Order by disordered action in swarms

We consider swarms as systems with partial random synchronicity and look at the conditions for their convergence to a fixed point. The conditions turn out to be not much more stringent than for linear, one-step, stationary iterative schemes, either synchronous or sequential. The rate of convergence is also comparable. The main result is that swarms converge in cases when synchronous and/or sequential updating systems do not. The other significant result is that swarms can undergo a transition from non convergence to convergence as their degree of partial synchronicity diminishes, i.e., as they get more disordered. The production of order by disordered action appears as a basic characteristic of swarms.