Method: DETERMINE_NODE_LEVEL
Method: IDENTIFY_RELATIONSHIPS
Method: GET_CHILDREN_NODES
Method: GET_TOPOLOG_SORTED_TABLE
Method: SCHEDULE_FORWARD
Method: ADD_SCHEDULE_NODE
Method: SCHEDULE_NODES
Method: DELETE_SCHEDULE_NODE
Method: SCHEDULE_BU_FORWARD
Method: INIT_PATH_TO_ROOT
Method: SCHEDULE_BU_BACKWARD