Modus Operandi
/ ˈmoʊ dəs ˌɒp əˈræn di, -daɪ; Latin ˈmoʊ dus ˌoʊ pɛˈrɑn di

noun, plural mo·di op·e·ran·di  
[moh-dee -op-uh-ran-dee, moh-dahy -op-uh-ran-dahy; Latin moh-dee -oh-pe-rahn-dee].

1. mode of operating or working:
to investigate the modus operandi of the natural world.

2. one’s usual way of doing something:
Management’s modus operandi can make or break an event.

Abbreviation: MO