What is a Resource Breakdown Structure (RBS)?
The resource breakdown structure is a hierarchical view of resources by category and type — labor (by trade and level), equipment (by class), materials — so demand can be planned, aggregated, and tracked at any altitude. The unfortunate acronym collision with the risk breakdown structure is a deliberate exam trap: read the scenario's subject, not the initials.
Crossed with the schedule, it generates the resource histograms and answers the questions procurement and HR actually ask: how many riggers, which months, what class of crane.
Worked example
A terminal-expansion RBS branches: labor → civil (formwork, steel-fixing, finishing crews), M&E (electricians by certification class); equipment → cranes (crawler 250t+, tower), piling rigs; materials → structural steel, precast. Rolling it against the schedule shows certified HV electricians peaking at 34 in Q3 against a regional pool of 25 — a hiring-and-training decision made eight months early instead of a crisis discovered live.