kaplan question

A company is considering a project with a 3 year life producing the following costs and revenues:

Cost of machine 100,000
Depreciation of machine (for three years) 20,000 p.a.
Annual cost of direct labour 20,000
Annual charge for foreman (10% apportionment) 5,000
Annual cost of components required 18,000
Annual net revenues from machine 80,000
Cost of capital 20%

solution shown is
Revenue – components – labour = $80,000 – $18,000 – $20,000 = 
$42,000 / yr and then discounting it to calculate NPV

i can understand why depreciation is not excluded from revenue as it is a non cash expenditure.
My Question is
Why did they also did not reduct the Annual charge of foreman.
Is it because its a cost that is being apportioned among the cost centers, mean it will going to incur even if the project is not taken and its not being related to this particular project.So any apportioned cost is not considered while calculating net cash flow of a project. Am i right?