factor in, broker, agent, factor out, constituent, component, divisor, ingredient, element, determinant, more...

unrelated, irrelevant, extraneous, inconsequential, nonfactor

prime factor, composite factor, more...

important, major, significant, second, key, single, critical, third, decisive, only, common

main determinant,   something; decisive,   thing to consider,   cause contributor,   key consideration,   points to consider,   possible cause,   things that affect,   cause of problem,   the f in spf