Purchase system - audit procedures

A) Obtain a sample of orders in the order database agree details to GDN. Q: do we need to write from where the sample is taken (from which database) or we can just say: Obtain a sample of orders and agree details to GDN. > When describing procedures pretend you are explaining them to a 16 year-old, inexperienced student. That forces you to explain in detail. I think here it is better to explain where you are obtaining the orders from as orders (other than very recent ones) on the order database shold all have GDNs B)Procedure 1: For the sample of orders, agree to the inventory database. Procedure 2: For a sample of orders in the order database, agree details to the purchase invoice. Q: could you please explain what is the difference between procedure 1 and procedure 2? And what would be the best answer to the question what is the reason for these procedures / why are we doing them? > P1 agrees to inventory database; P2 agrees to purchase invoice. P1 lets is to ensure that orders do produce inventory that is accounted for in the inventory database upon receipt. P2 is to ensure that all orders result in invoices from suppliers. An order with no invoice (unless a very recent order) might imply that invoices are not being properly accounted for; an invoice without an order should not have been received, should not be entered into the payables system and should not be paid. C) Procedure 3: For a sample of purchase invoices in the purchase day book, agree details to the corresponding order. Procedure 4: For a sample of purchase invoices in the purchase day book, agree details to the delivery notes for items on that invoice. P3 agrees invoice to order (roders start the ourchasing process). P4 agrees invoices to delivery notes (the next stage in the ourchasing process). Invoices should be paid only if goods were both ordered and received. Q: could you please explain what is the difference between procedure 3 and procedure 4? And what would be the best answer to the question what is the reason for these procedures / why are we doing them?

many thanks for your very useful explanations :)