Quick Summary: The most efficient multi-client pick and pack scheduling works backward from carrier cutoffs rather than forward from order arrival. Build a configuration profile for each client, set wave windows that close far enough ahead of each pickup to pick, pack, and stage the orders due on it, apply client SLAs as priority rules inside each wave, and route every order to the pick method that fits its profile. Then measure on-time ready to ship per client, because the building-wide average hides the account that is slipping.