Hello,

My company currently work 12 hour shfts in the pattern of 4 on / 4 off. The management are wanting to change this, to 8 hour shifts, taking away the 4 on/ 4 off.

I have been asked to look into this and the pro's-con's of 12 hour shifts, case studies etc. Does any one have any exoerience of this?

TIA

I have analysed shift patterns for clients a number of times including comparing 8 and 12 hours patterns. This has usually been driven by COMAH, and has become a priority when changes have been proposed (usually changing from 8 to 12 hours, so opposite to you).

My conclusion is that neither 8 or 12 hour patterns are better than the other. They both have pros and cons. However, 12 hour patterns are far more popular with the workers, so be prepared for a tough time if you go ahead with a change to 8 hours.

Obviously fatigue is one of the main concerns with shift work. It is easy to focus on the hours at work, but rest hours between shifts seems to be at least, if not more important. Whilst an 8 hour shift may have some short term benefits with regard to fatigue, the better quality breaks on a 12 hour pattern seem to more than balance out any concerns.

One thing to be very warey of is how absence will be covered. It is usally acceptable on a 4/4 12 hour pattern for people to sometimes work an extra shift, because they still get a 3 day break. There can be a tendency with 8 hour patterns for absence to be covered by people working a double shift (i.e. 16 hour) shift. Even if they only cover an extra half shift they work 12 hours but will probably only have a short break before the next shift.

The HSE website is a good reference point http://www.hse.gov.uk/hu...ctors/topics/fatigue.htm