What advice do you have on writing an OER support form for duties based solely on an additional duty?

Was there any inspections associated with your role? If so claim credit for briefings and the outcome, if positive from inspections. If you mentor junior officers or enlisted soldiers, which we all do, capture those experiences. I'm sure you past APFT, support recruiting, Family support program and complete other annual requirements.

Secondly, did you improve or create safety binder/program. If so address these improvements. If this was your primary duty, did you also have other additional duties or titles in support roles? What was your position on the MTOE?

Third, did the unit pass COMET or another inspection? Did you volunteer to support that inspection or provide leadership to ensure the organization passed. Think outside the box and start planning and capturing for 2017. Sounds like your rater did not have quarterly meetings with you, which could be leveraged for your supporting docs.

Agree with CPT Ahmed F., go heavy on specifics and don't even try to be vague on anything. As a BN Safety Officer you undoubtedly implemented programs and policies that increased safety of your soldiers and allowed tasks to be completed without damage to equipment. Focus on those things and research how things were in the past, ie. be able to say you increased safety during x procedure by yy%. You can also look at how some operation was able to be completed ahead of, or on, schedule with no mishaps or damage to equipment, etc., etc. Go heavy on procedures you implemented and what effect those procedures had on the BN. An OER for a Safety Officer is actually fairly easy to prepare because your actions have very quantifiable impact on so many other areas, just look at what you did and quit thinking of it as some additional duty. Don't know how it's viewed in the Army, but in the Air Force serving as a Safety Officer was viewed as a requirement for promotion into senior command positions.

Help me clarify a few things. Was this additional duty in addition to something else you were doing officially or was it your sole task. If it was in addition to something else great but even if it was your sole duty your OER doesn't necessarily have to look bad. Stress numbers over vagueness. What percentage did you cover? How was the specific duty before you took over? What quantifiable improvement can you say you made over the previous numbers? Did you receive any accolades related to it? As the AD officer who or what did you affect. Numbers read better. For example, LT Garcia was top 25% of officers I have rated in my x amount of time as Company Commander vs LT Garcia was number 3 of 20 officers I have rated over x amount of.... the second one reads better. Hope this helps.