N+1 is a redundancy configuration that provides one spare unit beyond the number required to carry the full load (N). If any single component fails or is taken offline for maintenance, the extra unit maintains operation, protecting uptime without the cost of fully duplicating the system as in 2N. It is a common design for chillers, UPS modules, and generators.
Category: Resilience & Availability · Subcategory: Redundancy Topologies · Part of the AIDC Technical Terminology reference.