The following factors should be taken into account in the design of rosters for semi-continuous and continuous shift work:
6.1 The frequency of night work, weekend work and work on public holidays should be limited as much as possible for each worker.
6.2 The frequency of shift rotation should take account of the difficulties workers may have in adapting to night work.
6.3 It is preferable that shifts be rotated in a forward direction (morning to afternoon to night), bearing in mind workers' preferences, local conditions and difficulties in scheduling a long period of rest after spells of night shifts.
6.4 Night shifts should be no longer than morning and afternoon shifts. Where long night shifts are used they should be carefully reviewed to find ways to avoid excessive fatigue. Successive long night shifts should be avoided to the extent practicable.
6.5 Rest periods for shift workers should be scheduled to fall on weekends-a certain minimum number of times during a given period.