Proverbially, it's what you hope to do "with one stone"
[DOC] [TLE] Two Birds with One Stone | Q&A about words | Wordsmith.org [PAR] The expression about killing two birds with one stone is an embarrassment to the 
... the term "killing two birds with one stone" let alone why you might think it's an ... 
to explain the advantages of "being able to do two things in a single effort".