An on-site private cloud can provide elasticity only if the organisation is:

1. Elasticity depends on spare capacity being available somewhere. 2. A small estate has no slack to lend. 3. If an organization is large enough with diverse workloads, an on-site private cloud may provide elasticity. 4. So the answer is large enough. _Source: NIST SP 800-146, 'Cloud Computing Synopsis and Recommendations'_