The first step of canonization is the life and virtues of a holy man or woman cannot start until 5 years after death. This waiting period makes sure the person has an enduring reputation as sanctity as faithful.
The second step takes place after the 5 years waited. After this it is waived by the bishop and the person that died can petition the Holy See to allow the initialization of a cause for benification and canonization.
The last step of the canonization process is the deceased person must have a proven miracle or evidence of intercessory power of the venerable servant of God and thus of his or her union after death with God.