The last total renovation consult that we did on layout included the need to put the maintenance shops in the middle of the facility - not my idea, but that was what a set of plans called for. We did extensive risk analysis on the location - all the potential if's and known items that could and have happened came into analysis and with a containment surround built around the shops (3 separate shops + office - each interconnected) the plant now has a self-contained maintenance system that has a Non-GMP pathway marked off to the nearest point of delivery and removal of items.
It was a lot of work, not for the light-hearted to undertake, but it is doable and no issues at audit time were found or "glaring" to be written up.
With all that said - most of the facilities I have been in either have a fully contained outside structure that houses maintenance/mechanics or the shops/room/office is located adjacent to production but at one of the four walls and NOT in the center of production.
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