Hi,
If I understand you correctly you want to select something to controll access to mines.
To select the right something you need to select the best one - to define the best one is where business analysis comes in: define what are going to measure that will allow you to assess after implementation whether you selected the right one or not. Then define the target value that (if attained) means it was successful. Example: we will measure the number of access points it can handle and if it can handle at least 25 it will be deemed successful. There will be about 6 to 12 of these objectives as business analysts call them. Get these signed off by anyone who is authorised to stop your project and is involved in some way with it.
Now define what you need this thing to do in order to achieve the objectives. Example: the mechanism needs to allow new access points to be created. So long as you can prove that you need this functional requirement in order to hit the objective, that's fine. Get these signed off by anyone who is authorised to stop your project and is involved in some way with it.
Finally define what you need non-functionally - who can use these mechanisms, where (geographically), what times of day, what days of the year, what security access controls are required, what performance rates are expected and so on.
Now you can go to vendors and say "show me how you support all this functionality". Rate them for each function, and those that score highest progress with.
There's a lot more to this selection process but it would be good to know if I am answering the question you are asking first!
Guy