So, What is the Process?
Set of actions to be followed to attain the expected output with minimal or no impact.
Actions are defined based on the previous our experience (external inputs) and getting matured and refined over new experiences.
It is a kind of re-usability component in non-technical area.
E.g. Agile-Scrum process

Benefits of the process so far, I’ve observed
“Searching and learning is where the miracle process all begins” — Jim Rohn
As mentioned the predefined process will help us in the following ways.
To smooth the flow of any series of activity.
To benefit the Resource utilization effectively
To avoid the surprises
To avoid the previous mistakes (which will be updated in the process)

Success ratio is defined by the group of people
If the process needs to be successful, the entire group needs to be aware of and needs to be trained to attain the benefits.
Do we need really process?
If the organization is small, the process will become burden.
If the organization is very big, the process is mandatory to move in rhythmic way.
Complexity
The Process needs to be simple enough and straight forward.
The Process should be defined to meet the outcome.
If the complexity increases in the process, then process will provide the exactly the opposite output of the process goal, end will be in chaos.
So Keep the Process Simple and get aligned with everyone and keep on refining the process with learning.