From Longman Business Dictionary
harmonizehar·mo·nize /ˈhɑːmənaɪzˈhɑːr-/ (also harmonise British EnglishBrE) verb [transitiveT] to make two or more systems, sets of rules etc more similar so that they work better togethera European Commission directive to harmonise rules on copyright in different EU countries
—harmonization (also harmonisation British EnglishBrE) noun [uncountableU]monetary union, followed by rapid harmonisation of tax and social laws