After action review An after action review ( AAR ) is a structured review or de - brief process for analyzing " what " happened , " why " it happened , and " how " it can be done better , by the participants and those responsible for the project or event . After - action reviews in the formal sense were originally developed by the U . S . Army although less structured de - briefs after events have existed since time immemorial . Formal AARs are used by all US military services and by many other non - US organizations . Their use has extended to business as a knowledge management tool and a way to build a culture of accountability . An AAR occurs within a cycle of establishing the leader ' s intent , planning , preparation , action and review . An AAR is distinct from a de - brief in that it begins with a clear comparison of intended vs . actual results achieved . An AAR is distinct from a post - mortem in its tight focus on participant ' s own action - learning from the review is taken forward by the participants . Recommendations for others are not produced . AARs in larger operations can be cascaded in order to keep each level of the organization focused on its own performance within a particular event or project . Formal AAR meetings are normally run by a facilitator , and can be chronological reviews or tightly focused on a few key issues selected by the team leader . Short cycle informal AARs are typically run by the team leader or assistant and are very quick . After action reviews in the military . There are basically two types of military AARs — formal and informal . Formal AARs require more detailed planning , preparation , and resources . They are normally scheduled and conducted as a part of external and internal evaluations . Informal AARs require less planning and preparation than formal AARs and are often on - the - spot reviews of soldier and collective training performance at crew , squad , or platoon level . Formal . Formal AARs are normally conducted at company level and above . However , when a training event is focused at squad or platoon level , and resources are available , a formal AAR may be conducted to gain maximum training benefit . Externally evaluated lane training , small - unit ARTEPs , and tank and BFV gunnery tables are prime examples . Informal crew , squad , and platoon AARs are held prior to company and higher - echelon AARs . The AAR facilitator ( evaluator or controller ) provides a mission and task overview and leads a discussion of events and activities that focuses on the objectives . The discussion with leaders and soldiers should orient on the use of terrain integration of key BOS ( Battlefield Operating Systems ) , and leader actions . The discussion should also examine the weapons systems and doctrine used by the enemy during the exercise . At the close , the AAR leader summarizes comments from the observers , covering strengths and weaknesses discussed during the AAR and what the unit needs to do to fix the weaknesses . Informal . Informal AARs are usually conducted for soldier and crew - , squad - , and platoon - level training or when resources are not available to conduct a formal review . They are often held for lower echelons prior to a formal company - or higher - level AAR , though they may be conducted at company level . Informal AARs are extremely important since they involve all soldiers and leaders in the participating unit . The formal company AARs for the training event depend on these thorough , informal reviews . These are sometimes referred to as a hotwash . Informal AARs are conducted similar to formal AARs and may be done for large or small units . They may be scheduled , or leaders may do on - the - spot reviews during the training . Discussion comments could be recorded to use in follow - on AARs or to apply immediately the lessons learned as the exercise is repeated . To apply this tool ask yourself and the team . - What was planned ? - What actually occurred ? ( facts not judgments ) - What went well and why ? - What can be improved and how ?