Is there an optimal sleep-wake pattern in shift work?

This paper finds that shift work clearly affects sleep and wakefulness but that there is very little known empirically about optimal sleep-wake patterns--except for the ones commonly used but not evaluated, for example, extension of morning sleep after night work, split sleep (main sleep + nap), nap positioning and duration, delay of main sleep, full commitment to night work (including bright light), phase advance and napping in relation to morning work, and modification of sleep strategies depending on the speed and direction of rotation. Thus computer simulations of the efficacy of alternative strategies must sometimes be used. The paper tries several such approaches and finds some possible ways of optimizing sleep. Still, the need for empirical data is emphasized.