参考回答
Consider the scenario below to answer the question:
A software project is estimated to take 24 person-months of effort and 110 calendar days to finish. At a checkpoint, the project has consumed 16 person-months and 70 calendar days. What %age of the project is completed?
Note: This question can be easily customized to include a business analysis context. So don't consider it to be a project management question.
This question needs some consideration to be answered correctly. Let's consider the facts provided.
Total estimated effort = 24 PM (person-months)
Note: A person month means the amount of effort a person will spend in a month. Considering 22 working days, on average, it will be 22 days of work.
Effort spent at checkpoint = 16 PM
So, the completion status = 16/24 = 66.67%
But, this calculation has one major assumption. In this case, we are assuming that the effort spent is equal to the work completed. The effort spent at this checkpoint is indeed, 66.67%.
But, can we say that the team has also completed an equivalent amount of work? It's not easy to estimate.
So, how do we estimate the correct status? This is done by estimating the effort required to complete the remaining work. Let's consider two scenarios to understand it.
Scenario I
Total estimated effort = 24 PM (person-months)
Effort spent at checkpoint = 16 PM
The remaining effort to complete = 10 PM (This could happen because of various reasons like resources leaving, challenging tasks, etc.)
So, the completion status = 16 / (16+10) = 61.5%
Why did I consider (16+10) as total effort? That's because, at this checkpoint, 16 person months are already spent. The remaining work will take 10 person months, so the total effort = 16 +10 = 26 PM.
Scenario II
Total estimated effort = 24 PM (person-months)
Effort spent at checkpoint = 16 PM
The remaining effort to complete = 6 PM (Not so frequent case but can happen)
So, the completion status = 16 / (16+6) = 71.7%
In this case, the total effort has been reduced.