Vavala is a retired Army National Guard officer who served as the Adjutant General of the State of Delaware.
He received the promotion in February 1999 after the retirement of Major General George Hastings.
In January 2017, Vavala was promoted to lieutenant general in the Delaware Militia.
In April 2017, Vavala was promoted to general, in the Delaware Militia, in honor of 50 years of service.
He is the first Delaware National Guardsman to achieve four-star rank and one of the very few American service members to have risen from Private to 4 Star General.As the Adjutant General, Vavala was the highest-ranking member of the Delaware National Guard.
He was responsible for managing the affairs of the Army and Air National Guard and for advising Governor of the State of Delaware, who is the Commander-in-Chief of the Guard.