"To set a baseline" means to establish a starting point or reference from which progress or changes can be measured or compared. It helps to understand if something is improving or deviating from the initial state. Full definition
So, the idea is to set a baseline for what is good value for that thing and then try to decide. (policygenius.com)
From our experience, the tool helps in setting a baseline of current practice on which to build capacity for improvement, wherever that baseline may be. (teachermagazine.com.au)