This purpose of this system is to run a company from a single person to about 100 employees.
Running a company can be split by specific job functions:
First of all the company has to be promoted so people know it exists, and the products or services it is selling. That is done by the Marketing & sales functions
When the company is known by its target audience, there should be a possibility to order its products or services either by an E-commerce site, social media, email or telephone. Incoming orders are handled by the Order management function
When physical product orders do come in they need to be packed and shipped by the Inventory management function.
In order to make sure financial records are recorded when they happen in the operational functions then Accounting will automatically generate invoices and payments from the incoming order and will be posted into the ledger.
In short, how to process an incoming sales order?
Approve on the sales order list.
Pack and confirm on the outgoing shipment list.
Result
full record of the product -> order -> shipment -> invoice/payment -> accounting ledger