This applies on complex plans and things you don for the first time
- If you didn't do it before, then you don't have much experience about it, and you don't have a good mental simulation because you are missing information and don't know exactly what you are doing, so you tend to underestimate the time it will actually take to do it
It always take more time than expected, for any unforeseen issues, unpredictable tasks, problems to handle, unexpected situations …. Etc.
It is a very normal things and it happens with most people all the time
We are bad at predicting deadlines and milestones time-points, we don't know what will happen in the future … people are almost never on schedule
So what is the solution to that?
- It is not but extra weeks, months for slacking … BAD IDEA … it will just make people postpone and fit their work into the new extended durations
- It is not assigning more people to it … communication overhead will just hit the sky and you it will take much longer time
The best solution is to divide the plan into certain small tasks; they are easier to predict … then put a small buffer time for but you don't tell people about it
And probably you will also be late on schedule
Here is the ingenious rule of this:
"It always takes longer than expected, even if you take into account this law"
- Be patient with yourself
- Understanding that being always a little late for schedule will make everyone work fast and do their best and there are no intentional slack time
- Always assume that your schedule isn't quite right
And the best strategy to deal with this fallacy is to understand that:
"Plans are useless, but planning is indispensable"
- The process of planning is the actually useful thing
- Plans are just in-process guide to keep you going in the right direction
- Deal with plans as processes more than some deadlines
- Adjust as you go and deal with them constructively