Employees can create and track any EPO (Expense Purchase Order). They can attach any documentation as well. This EPO can be reviewed by the higher authority and can be approved/accepted from one/more than one authorized member. Once the EPO approved, the item goes for the order.
Also, have the document management system, where different kinds of documents (like, ECN, FCD, LIT, SOP) are attached for the purchase order. The system is a role based application, where each employee has their own role, and can perform accordingly.
