Hola Emanuel
haya hecho could refer to I, she, he or you formal (usted); their conjugation coincides here; so the only way to know the subject is by context.
In this sentence:
Es probable que haya hecho toda la tarea antes de ir al concierto.
It's probable that I'll have done all my homework before going to the concert.
there is not enough context to know, it could be I, she, he, or you formal.
Saludos
Inma
