WMS: the details
It covers the full cycle: receiving, putaway, replenishment, picking, shipping and inventory. Unlike an ERP’s warehouse module, which knows how much stock there is, the WMS knows exactly where it is and decides the work: it groups orders into waves, sequences the lines to shorten routes and guides the operator with a handheld or by voice.
It integrates with the ERP, which sends it orders and receives confirmations, and with carriers, to whom it hands labels and manifests. When the WMS doesn’t cover a case specific to the business—a location type, a picking rule, a report—the sensible move is to extend it through its API rather than replace it.