What your business should do is undertake a project. This means have someone specifically assigned to the role of discussing with potential vendors, partners and VAR's (Value Added resellers). Having a clearly defined project manager will ensure the project does not fall to the wayside and get forgotten about. It will also ensure that a person inside your organisation is able to convey the different pros and cons of the system to your staff.
The next step would be to define your requirements. This means defining certain procedures you would like your next system to be able to do. In this example I will use a company deciding on Accounting Software. This company may be interested in an FinancialSystem which is also able to provide inventory management. Therefore they will need to define how they would envisage the process working between their inventory and their accounts. In most cases a demonstration of suitable Accounting Software will give stakeholders an idea of how different systems undertake the process and will also help to fine tune your requirements and specifications.
One aspect which is rarely thought of throughout the process is considering the company's customer service. If you are unable to speak with a real person over the phone, or see them in person then it may be not be surprising if things don't change after you have purchased. Some Accounting Software company's encourage personal contact while others do not.
In summary, this guide should give you an idea of how you can sort out the wheat from the chaff ofsoftware as well as many other business systems you require.