Calculate completed operation and date difference

Anonymous So, yes, as a column:

Completed? Column = 
  VAR __serial = [serial #]
  VAR __table = FILTER('Table',[serial #] = __serial && [Operation #] = 30)
RETURN
  IF(COUNTROWS(__table)+0 > 0,"Y","N")

The second part is essentially MTBF, See my article on Mean Time Between Failure (MTBF) which uses EARLIER: http://community.powerbi.com/t5/Community-Blog/Mean-Time-Between-Failure-MTBF-and-Power-BI/ba-p/339586.
The basic pattern is:
Column = 
  VAR __Current = [Value]
  VAR __PreviousDate = MAXX(FILTER('Table','Table'[Date] < EARLIER('Table'[Date])),[Date])

  VAR __Previous = MAXX(FILTER('Table',[Date]=__PreviousDate),[Value])
RETURN
  __Current - __Previous