Diagram (A) in Fig. 9 represents a scenario with the highest
probability of task completion, and diagram (B) shows the certainty
of failure. Referring to Fig. 8.1, a reliable assignment
determines what WILL be done, after considering what
SHOULD and CAN get done based on the situation at hand.
The assignments in diagram (A) are well defined, sound, in the
right sequence, and doable by the crews. Thus, the task is likely
to get done at the required time. In contrast, the assignments in
diagram (B) are out of plan and have much variability to be
controlled. Thus, the probability of task completion decreases.
The Last Planner System has four levels [50]: (1) Master Schedule: setting milestones and strategy identification of long
lead items; (2) Phase Schedule: Pullk planning (specifies handoffs;
identify operational conflicts); (3) Look-ahead Plan: Make
Work Ready Planning (to ensure that work is made ready for
installation; re-planning as necessary); and (4) Weekly Work