Today, almost all computer systems allow multiple processes to run at the same time.
When multiple processes running at the same time, means that when one process is blocked waiting for input/output to finish, another one can use the Central Processing Unit.
Therefore, multiprogramming increases the central processing unit utilization.
To achieve multiprogramming, the simplest way is just to divide memory up into n partitions (normally unequal partitions).
Multiprogramming lets the processes use the Central Processing Unit when it would be.
The Central Processing Unit (CPU) utilization can be improved when multiprogramming is used.