Critical path is an
important element in project scheduling. Every scheduler or planner officer
need to identify which is the task(s) that will form the critical path of the
project. Critical path always consist of series of task or work that must not
be delayed, start or commencement date and must finish on a fixed date. If
there is any delay occurred in commencement of any task or work that form a
critical path, then there is very high possibilities that the project going to
be delay in completion. When this situation happened, contractor will have to
plan for a catch-up program to make sure that the project can be completed
with-in the approved construction period. However in this section we will not
discussing on the catch-up program or plan.
How to determine the
critical path of a project? In actual fact, regardless of what scheduling
software that planner(s) officer or Scheduler(s) officer used to produce a
work program or work plan for a project, the basic theory of the Critical path
calculation is always the same for any brand of project scheduling software.
There are two types of
critical path calculation that can be used to identify a critical path. The two
types of calculation are Forward pass calculation and Backward
Pass calculation.
Forward pass calculation
can be used to determine when or on what date a project can be completed. The
calculation will start from the beginning of the project and at the end we will
be able to know when a project can be completed with estimated numbers of resources
that available.
Backward pass calculation
can be used when we are given a fixed date on when to complete a project. This
method always required us to analyze the availability of our resources and
their output in order to complete the project as required. By knowing our
capacity of resources we will be able to estimate the duration required to complete
each and single task of a project. With this information than we start the
calculation from the given finished date and we will know the latest date we
must start our work which normally known as late start.
Theoretically, Critical
path will always having the same figure for the early start and the late start.
Thus there is no number of floating days allow. Mathematically the float day is
equal to “0”. All series of task or works that have no float days or “0” floating
days will fall in a critical path of a project.
