The phrase "optimum condition" refers to the best or ideal state or situation that something can be in. It is when everything is working perfectly or at its highest level of efficiency. Full definition
He hardly seemed to be in optimum condition for what could be the most important days of his life. (si.com)
This ensures that you are getting the very same parts that your vehicle was shipped with, keeping your vehicle in optimum condition for quality performance. (coggintoyota.com)
The goal is to create optimum conditions for a positive outcome. (coloradosurro.com)