Here is a list of questions to help when choosing an open-source ERP solution. It does not claim to be exhaustive but these questions absolutely have to be asked according to me.

• Which have been my Business Management best Practices until now and why? The point is actually to identify which practices have worked well to run your Business -whatever they require Computing or not- in order to evaluate if you will be able to do as well or even better with an ERP System. 

• What makes you think you need an ERP? From that you can create a list of required Features for your future ERP. But this Question is quite different from "what you would like you ERP to do" -this one has to be asked just after.

• Does your Organization have the IT Resources necessary to support an on-premise Installation?  A Company has to consider on-demand or hosted Solutions. If it meets the Company's needs, it will have the advantage to cut its costs.

• What is the true Cost of the ERP Solution? Do you have to pay for a License?  What will be the Costs for Implementation Services, Maintenance Fees and Upgrades? These points have to be considered before making a Decision...

• What kind of Services will your Organization require from the ERP Vendor? Make sure that the ERP provider offers adequate Support Services, Training and that it has got a long-term Product Strategy. The open-source -with an available Source Code and many Developers- is often a Proof of Durability.