We are a small business and use Xero.com (which is an accounting system without ERP functionality).
What we have found that we have at times lost track of items requested by the customer, and have found a couple of occasions where equipment/services delivered have not been invoiced.
We have forms for Invoice, Delivery Note, and sometimes (not always) a client purchase order as a reference.
We do not have any paper structure that ties this together, so what would be the best way to have a ledger/form to include in our business processes that will drastically reduce the chance of things being given for free?