shortfall vs insufficiency

shortfall and insufficiency both are nouns.

Word	Noun	Adjective	Verb	Adverb
shortfall	Yes	No	No	No
insufficiency	Yes	No	No	No

As nouns, insufficiency is a hypernym of shortfall; that is, insufficiency is a word with a broader meaning than shortfall:

shortfall: the property of being an amount by which something is less than expected or required
insufficiency: lack of an adequate quantity or number

Other hypernyms of shortfall include deficiency, inadequacy.

shortfall (noun)	insufficiency (noun)
the property of being an amount by which something is less than expected or required	lack of an adequate quantity or number
	(pathology) inability of a bodily part or organ to function normally
	a lack of competence