Well first of all the Supplier and the consultant will obviously have a different opinion of the ERP system.
It depends on what context you are talking about supplier.
An ERP is a full Software system that should be able to carry out all the company needs e.g Entering parts, stock, stock control, purchase orders as well as dealing with invoices etc.
The ERP would also have some sort of administration content e.g. A superuser or users who can create accounts for users who may only need to access certain parts of the system that they may need.
E.G. The production manager may only need access to Stock, Warehouse stock control etc.
Whereas acounts and Administration who deal with orders and invoices may also need the Acountacy and purchase ledger module of the ERP.
That said if we look at the supplier as merely supplying the Software they will need to give the enduser (Client)guarantees of Software patches, upgrades, updates and presumably tehnical support as they should know the current Software pitfalls.Maybe even tied in with the consultant at various stages of the project.
The consultant would try to obtain as much information as possible to achieve a pre installation plan for the client.
A post installation plan to ensure the ERP is supported.
It is very difficult to do this as all companies work in different ways.
We have recently had an ERP installed and the consultant was part of the Company who sold the ERP Software.
First thing was meeting and demo of Software then a Q & A session with the consultant.
At this stage a project plan was drafted and again it depends on the companies way of doing things.
Sorry i can't elaborate anymore and hope you can at least get something from this answer
