Critical Chain Project Management
Almost all projects fail in terms of timings and costs, but this is not because we don’t plan
carefully enough, but rather because we plan to fail. Main reasons for wrong planning are:
1. We plan assuming our project will not change its scope, but it always does. You will
never find a project where the scope never changed during the project phase. In the
best case, the change was minor, but usually changes are significant enough to impact
your project. The question is: if we know the plan will change, why do we plan assuming
it will not?
2. Tasks end after the deadline or in the best case the last day: A project is made of tasks,
and the probability of tasks ending before the deadline is zero, which means that the
probability of a project ending by or before the deadline is also zero. This is due to 2
main factors:
a. Student’s syndrome: as students do, if I know I have enough time I’ll start my
tasks after the project’s start of that tasks (i.e. if I have 10 days to perform a
task but I know I can do it in 5 days, I’ll probably start day 3, 4 or 5, which
means I’ll eliminate the safety stock from my tasks and may, in the best case,
finish that task the last day (if nothing happens)
b. The last 20% is the slowest: when you look at how people advance in their
project they usually get very fast to the 80% completion of a task but take much
more time for the last mile. When people start early and get fast to the “80%”,
they tend to relax or if they know that they may finish earlier they spend more
time than needed improving details that are not really needed or just wait until
the last day to end their tasks.
Additionally people don’t tend to finish ...