Question 1) So lets say we have a wall that is 400 sf of area. Lets say one labor can produce 40 sf of wall per day. Then we have 400/40=10 days for 1 labor to build this wall. So this is the duration required to build this wall. Is this also equal to work now? Because work = duration x units, so, 10x1 = 10 days = 80 hours?
Question 2) Now, if we had a labor that could produce more, say, 50 sf of wall per day, then we have 400/50= 8 days to complete the wall, which is the duration. But now with same logic the work is changed to 8days x 1 unit = 8 days = 64 hours.
So we have the same wall, but depending on the skill of the worker, the amount of work is different. It doesn't make sense to me that the amount of work required to produce the wall is different in both cases. It is the same wall. Why the amount of work to build it is different?
What I should have done in the second question was, saying that the more skilled resource is 50/40 = 1.25 times more effective, so, when calculating the work, I should have said 8days x 1.25 units = 10 days = 80 hours again? Because the skilled unit is worth 1.25 of first unit? - If so then it makes sense. This is the way we should think correct?
EDIT: I am asking the question from simply the point of view of proper project management practices and Earned Value Analysis (EVA) purposes only. Such as in Work = Units x Duration. The question is not in broader context of life. Simply in the context of EVA in project planning. That's all.