substitutability

/ˌsʌbstɪˌtutəˈbɪləti/
noun
  1. The quality or ability of one thing to be used in place of another.
    • Economists study the substitutability of different energy sources like coal and natural gas.
    • The substitutability of butter and margarine makes it easy to adjust recipes.
    • In team sports, the substitutability of players allows coaches to rest tired athletes.