Subjective planning consists of goals and objectives where you know when you have achieved them but you cannot put a concrete number to it. If your goal is a peaceful life, there is no way of measuring how close you are other than your subjective experience.
Objective planning consists of the goals and objectives where you can quantifiably measure the outcome. If your goal is to save $10,000 you can always exactly know how close you are.
In all life areas, a mixture of subjective and objective is ideal. In any given area determine both objective and subjective goals and spend the time to make sure the two make sense together.
Having the objective goals gives structure to how you are measuring and achieving your subjective goals.
The more perspectives you have for your life journey, the more fulfilling the journey will be.