Tine's Heimdal factory in Norway did do 30 hour work week for a while - with good results in efficiency (and employee happiness). It was unfortunately scrapped

Tine's Heimdal factory in Norway did do 30 hour work week for a while - with good results in efficiency (and employee happiness). It was unfortunately scrapped due to cost concerns (workers kept same pay as for 37.5h work week). Its not clear if the change back to "normal" week was entirely rational - there were other suggestions to make the cited target of 80M NOK/year savings.