Rationalizing RPO

Answer: Basically the RPO means a volume of data stored/processed in a time frame before the occurrence of a disruption that the organization accepts to lose. For example, if you have a RPO of 4 hours, it means the organization accepts to lose stored/processed data in the last 4 hours before the disruptive incident.

Since the variables to evaluate such loss will depend of the business process evaluated, there is no general formula to apply (e.g., for a sales website the number of transactions lost can be a parameter, and for a cloud storage service the volume of data lost can be the parameter). The way to rationalize RPO is by assessing the damage for different amount of data loss - then they will be able to recognize what is acceptable and what is not. 

This article will provide you further exp lanation about RTO and RPO:
- What is the difference between Recovery Time Objective (RTO) and Recovery Point Objective (RPO)? https://advisera.com/27001academy/knowledgebase/what-is-the-difference-between-recovery-time-objective-rto-and-recovery-point-objective-rpo/