Extensive due diligence of multiple suppliers is severely overrated! When choosing a software supplier, select the ones who are overrepresented in your industry and companies of your size. All information is available on the internet. A selection does not need to include more than three software suppliers.
Focus instead of doing a large number of visits to companies that have used the various suppliers. Was the implementation according to expectations? Does the processes in the system now function end to end? What was the total cost, including consulting services?
The majority of ERP systems today are fairly well integrated internally between the different parts of the software, but what is much more important is how the ERP system can be integrated with other systems, vital to the company’s business, in particular the customer-oriented applications and processes. The company’s business will rapidly change over time. Therefore, it is vital to evaluate how well the ERP system will meet the customer requirements of tomorrow?
From the perspective that the ERP system is supposed to support how the company can develop its proposition to its customers, the license cost is more or less irrelevant. The biggest “cost” lies in inability to adapt to market changes and high IT cost for changes in the system. This cost can be high even in comparison with the total cost for an implementation.
In short: Use a small selection, make many visits, the major focal point is tomorrow’s customer requirements, and don’t forget to the major cost, which is lost revenue.