Hi Jim, as you say there is pros and cons to both and I work in a department that has tried both. I'm not sure what is more cost effective but the benefits of in house is that you have a specialist on site during the working day and this is very good for the theatre staff and the EBME dept. I don't think the 24 hr cover is important as out of hours the staff should always have access to another machine. The techs would be considered as specialists in anaesthetic equipment and although there may not be enough work on anaesthetics to cover the techs time I'm sure they could cover other kit in the hospital to a lesser level. As for liability I would say that if you have a competent tech/engineer then the risk would be minimised, and also dont forget that some external techs are maybe not the best either.The one concern I would have is if you spend the time and money training one or two techs to be specialists in anaesthetics equipment they could easily leave as and when suits them taking all that valuable experience with them which could cause a problem. What would you do then, train other techs to come in or fall back on external companies?