This article (linked below Read More) contains some very useful insights about how to think about grid reliability and resiliency. Here are some key insights, IMO:

One definition of reliability is a power system’s ability to deliver electricity to consumers in the desired amounts (Zappa et al., 2019). Reliability can be measured by the frequency, magnitude and duration of power outages

we consider resiliency as the response to a disruptive event (Phillips, 2019). In other words, it refers to the grid’s ability to recover from power outages and blackout

Resiliency is the time it takes to reduce the magnitude of power outages and return the system to normal operations.

reliability and resiliency can be described using three variables, which are the frequency of power outages, the average duration of power outages and the average magnitude of power outages.5 The total shortage of electricity volume from the grid corresponds to the product of these three variables.

We suggest that reliability and resiliency are not enough to correctly describe the social impact of outages. We propose adding adaptability, in a broad sense of non-market and non-power system actions, to the reliability and resiliency lexicon. We define adaptability as actions that can mitigate the human and economic costs of outages as they occur, which can be substantial.

adaptability depends on broader policies than those related to the power sector such as policies and investments pertaining to other critical infrastructure. Furthermore, there are important physical, market and regulatory dynamics between these components that affect RRA. For these reasons, markets alone cannot ensure an efficient level of RRA

My takeaway is that RRA is a measure that should be applied to a community, City, State and even at a Country level. It would provide insights into the reliability and resiliency of an electric grid servicing an area AND the policies and practices that help a population cope with disruptions to electric service, this is the adaptability component in RRA.

IMO, an RRA measure should be included in the set of metrics describing the demographics of an area to give potential buyers and investors a sense for how reliable the electricity service is in an area and a sense for how a community supports itself through those unexpected times when an outage occurs. Reliability and resiliency are measured using the three variables identified above (frequency, duration and magnitude of outages), but adaptability must be measured by analyzing public policies that are designed to help people cope with electricity disruptions. This makes sense to me, thanks Dr. Felder and Marie Petitet for sharing your analysis and insights. RIP old LOLP equation, step aside to let RRA pass by.