The orientation phase is the most critical of the OODA cycle; the other phases are more or less instantaneous actions, whereas orientation is the space in which there is the greatest opportunity (as well as the greatest risk). Sensemaking means either developing a narrative from observed facts or applying an existing narrative (a mental model) to the situation.
The orientation phase is where the OODA loop is most vulnerable to disruption. The OODA loop can be disrupted by a competitor speeding up their own tempo to overwhelm their rivals with new data; by acting in an unexpected, forceful way; or by subverting orientation with false impressions that cultivate an inaccurate mental model.
Chin, Cedric. “Much Ado About The OODA Loop.” Commonplace - The Commoncog Blog (blog), May 19, 2020. https://commoncog.com/blog/much-ado-about-the-ooda-loop/.