What are the stated purposes of juché and songun?

In North Korea, Juche stands for self-reliance though this has taken a broader meaning it is the country's political system which means that a person has control over his or her destiny. It is a set of values that North Korea has embraced. Songun is its military first policy which has dominated many aspects of North Korean life. Songun is the "military first" policy of North Korea, prioritizing the Korean People's Army in the affairs of state and allocation of resources.

They made a checks and balance system to equal power within the branches. the "check" meant that one branch would watch one branch and "balance" them if they were too powerful. if you want more info on this, i would just google checks and balance system.