Test estimation is a method of estimating the resources to be used in achieving deadline of a project. A test estimation is very important in assessing budget, manpower, time and other resources that is supposed to be allocated to the project.
Total Effort = Total function points * Estimate defined per function point
A plan may go through a lot of upheavals due to absence of required members at the time of planning, an unpredictable situation may arise like a member leaving the job at that point of time due to some unforeseen circumstances and so on.
The only approach one must follow in pursuit of a successful goal is consistency and perseverance to proceed despite of all the odds.