Employee: (start missing something) user Specify the need script Check if goods are in stock Goods in stock? Yes Officer: user Approve good allocation Employee: manual Use goods from stock ... Goods in stock? No user Create purchase requisition Officer: user Approve purchase requisition Central procurement: user Check purchase requisition script Create order from purchase requisition Officer: user Sign order Central procurement: send order Warehouse: manual Wait for order delivery (timer no delivery in 1 month) Central procurement: user Contact supplier manual Wait for order delivery ... ... Warehouse: manual Wait for order delivery (receive delivery of goods) Unpack shipment Central procurement: user Check quantity and quality Employee: Use newly delivered goods