Military Job Description

I’m reading a biography of a man who served in the US Army in Vietnam, and it says that he was an S3 Operations Officer for a brigade of 5000 soldiers. What exactly is an operations officer, and what would his duties have been?

The Operations Officer is essentially the senior vice president of operations for the organization.

Brigade S3 is a very responsible position with a lot on the line, even in peacetime.

Not exactly sure what he would do on a daily basis. But I can be a little more specific than LSLGuy.

S3 Operations manages the brigade’s assets. It’s a desk job that tasks out the resources available to the brigade. This can be personnel or equipment.


The ops officer in a Seabee battalion was responsible for all the construction projects and any tactical exercise logistics, such as movement of equipment and troops. A heavy-duty position.

I guess what I’m wondering was whether an S3 would have a role in developing battle plans. Would he have been sending people into combat, devising attack plans and so forth? Or is this more of an administrative role, rotating troops in and out and overseeing supply lines?

Ok, I can help you out a bit here. I was in the HHC for 3rd BDE 1st Cavalry Division for 2 years in Ft. Hood–spent a year in the S-2 Shop and a year as a armorer and mail clerk.

In an Army battalion HQ or higher (brigade/division/Corp) there are 4 Sections:

S-1 Personnel
S-2 Intelligence
S-3 Operations and Training
S-4 Logistics and Supply

For some independent brigades, or division and higher, a 5th shop is added: S-5 Civil Affairs.

The S-3, the officer in charge of the section, is responsible for all operational planning of the unit. This includes formulating and distributing battle plans (areas of responsibility and objectives) as well as training (what type/when/where). The S-3 shop is the largest section in any HQ and is constantly busy.

The S-3 must be able to work with the CO, XO, and be able to integrate information from all of the other sections as well as setting the objectives for the sections. He is by far the busiest person in the unit and has the most stress. Of course once an officer has successfully completed a tour as a S-3 he will be nearly guaranteed an XO slot himself in the near future.

Xgernina did a beautiful job of explaining what I wasn’t willing to spend the time on.

An S3 and his staff does a LOT of battle planning and followthrough execution thereof. In peacetime that’s the execution of training plans, getting units into the field, arranging the mock enemy and then “fighting”, as well as all the classroom training and small unit drills.

In wartime the enemy conveneintly arranges himself, but now the fighting loses the quote marks.

Imagine the VP of manufacturing in a manufacturing company or the warehouse manager in an warehousing company. This is the guy that everyone goes to for any real-time problem.

As Xgernina said, it’s a critical step on the road to your own command and probably the best hand-ons leadership job in the military. The USN & USAF have similar functions by different names.