The first question I ask when implementing a financial system

I have been implementing financial systems during the past 4 decades. In my experience, it does not matter which vendor solution is chosen; There are some critical success questions that need to be discussed. I don't want to oversimplify the situation, however, the key is to set the context for the current state (i.e., the 'as-is').

I simply open with the question: "are you happy with your chart of accounts?"

If the answer is 'no', then I know that there is a high likelihood that there is going to be some business process re-engineering required BEFORE we go too far in implementing the system.

If the answer is 'yes', I will probe a bit deeper by discussing some key day-in-the-life scenarios for their key accounting transactions (specifically, Accounts Payable invoices and Accounts Receivable invoices.) The objective is to ensure there are no hidden issues in their processes that need resolution before proceeding.

In summary: A financial system implementation can fail when designed without a proper understanding of the business's unique requirements. By addressing the business needs and potential issues early on, you prevent starting down a path you will later regret.