WMS (Planning): This controls the incoming and outgoing inventories and performs tasks like receiving orders from the customers, assigning inventory, creating invoices and shipping labels etc. It interacts and exchanges the details with WCS, but on a non-real time basis.
WCS (Control): This is the main traffic cop which manages and interfaces data on real time basis. It receives the data from the WMS, directs and coordinates with systems like conveyors, sorters, print & apply systems to accomplish the tasks.
WES (Execution): It’s a hybrid system which performs some combined tasks of WMS and WES. The WES organise sequences and coordinates between the man and machine to move items inside the warehouse.