Scalability (scalabilité)
The ability of a business model to grow revenue without proportionally growing costs. A scalable model sees its margin expand with volume. Software is the canonical example: the marginal cost of distributing one additional copy is near zero.
In practice
Scalability is measured by how the revenue-per-headcount ratio evolves over time. A consulting firm bills time: doubling revenue requires doubling staff. A SaaS at 1 million euros ARR with 10 employees can reach 5 million with 20 — the ratio improves. In a franchise network, scalability comes from franchisees contributing their own capital and teams. The network head grows royalty income without hiring in proportion.