I would say that the sentence is not correct, and a corrected version would start with 

> "The miss _of the_ sales target..."

 or 

> "The miss _of our_ sales target...

 or 

> "The miss of _the department's_ sales target..."

 or similar.

However, I think even the corrected version still sounds awkward and long-winded. Instead I would say 

> "We missed our sales target because..."

 or 

> "We missed our sales target. The miss was caused..."

or 

> "The department missed its sales target because..."

 or perhaps even 

> "Our sales target miss was caused..."

(That last one is a bit German in style, chaining three nouns in a row into a noun phrase -- I think it's acceptable in English, but I could imagine some people finding it confusing.)