Clinical judgment and sometimes ethical judgment enter into these decisions where there are often no right or wrong answers and where there are no textbooks or RCTs that tell us what to do.
predecessor - something that precedes and indicates the approach of something or someone. harbinger, herald, forerunner, precursor. indicant, indication - something that serves to indicate or suggest; an indication of foul play; indications of strain; symptoms are the prime indicants of disease.
This term is applied in particular to corporators who are now no longer such, and whose rights have been vested in their successor; the word ancestor is more usually applicable to common persons. The predecessor in a corporation stands in the same relation to the successor, that the ancestor does to the heir.