VP UTILIZATION TIME
As 1) VP can process only one task at a time (more under title Attentional Limit - in detail), unlike LB, which can execute multiple tasks by processing huge amount of data simultaneously (i.e. parallel processing), and as 2) VP is responsible for decision making processes, and as 3) VP is responsible for guiding actions, there is a tendency in DOS to save as much VP utilization time as possible.
Such optimization is done in operations where VP utilization can be reduced or eliminated without hindrance to the task's goal, e.g. while processing repetitive, condition based and genetically programmed interactions, as explained in the next topic.