You're reading the job description all wrong...you've got to think like a hiring manager in the defense industry to make any sense of it, i.e. reverse qualification priorities and the actual job you'll be hired to perform will become crystal clear.
Got to give the hiring manager some credit. Listing DOORS as a proficiency requirement is a sure way to prolong vacancy.
https://www.ibm.com/support/knowledgecenter/en/SSYQBZ_9.5.2/...