go ahead vs open its doors

go ahead

verb
  • To proceed with; to begin. 

  • Used to grant permission for or to give endorsement of a suggestion or proposal. 

  • To send communication over the radio. 

open its doors

verb
  • To begin operating. 

  • To allow or invite outside influence, investment or immigration. 

How often have the words go ahead and open its doors occurred in a corpus of books? (source: Google Ngram Viewer )