nonoperational vs unserviceable

nonoperational

adj
  • Not operating; not working. 

  • Not associated with operation. 

unserviceable

adj
  • Not working (machinery, etc). 

  • Unusable; of no use. 

  • Impractical. 

How often have the words nonoperational and unserviceable occurred in a corpus of books? (source: Google Ngram Viewer )