First, two concepts

RPO (Recovery Point Objective) = the maximum data loss you can tolerate. RTO (Recovery Time Objective) = how long the business can be down.

Recommended tiers by system

• ERP / Core production: RPO < 5 min / RTO < 30 min / active-active same-city + async off-site
• HIS / Hospital core: RPO < 1 min / RTO < 15 min / active-active same-city + off-site DR
• OA / Email: RPO < 4 h / RTO < 4 h / on-prem backup + cloud archive
• Office endpoints: RPO < 24 h / RTO < 24 h / file backup + versioning
• R&D data: RPO < 1 h / RTO < 4 h / on-prem + async off-site

How to pick the architecture

Hongguan runs a "gap analysis" — first assess whether the current backup architecture meets the business RPO/RTO, then propose a "right-sized, not over-engineered" plan.