IIoT, SCADA & Edge Connectivity worked example

Edge Device Count at 61% deployment uptime headroom: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop deployment uptime headroom to 61%, then walk the calculation through step by step. Estimate the count of edge devices needed in a rollout from sites in scope, devices per site, deployment uptime headroom (share of period the deployment is actually proceeding), and the share of devices that go in cleanly without rework.

The inputs for this scenario

  • Sites in scope: 24 sites (held at the documented default)
  • Edge devices per site: 3 devices / site (held at the documented default)
  • Deployment uptime headroom: 61 % (the input this scenario stresses; the baseline uses 85)
  • Clean-install rate: 95 % (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Gross edge devices needed = sites × devices per site.
  • Edge devices landing cleanly in plan works out to 41.72 devices at these inputs, and this is the headline figure for the scenario.
  • Gross edge devices needed works out to 72 devices at these inputs.
  • Deployment downtime loss works out to 28.08 devices at these inputs.
  • Replacement loss from DOA or damage works out to 2.2 devices at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where deployment uptime headroom sits at 85% and the headline result is 58.14 devices, this scenario comes in 28.24% below the baseline at 41.72 devices.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to deployment uptime headroom, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. It treats uptime headroom and clean-install rate as flat multipliers across all sites; sites with worse connectivity or harsher environments will deviate, so order spares accordingly.

Results at a glance

  • Edge devices landing cleanly in plan: 41.72 devices (headline result)
  • Gross edge devices needed: 72 devices
  • Deployment downtime loss: 28.08 devices
  • Replacement loss from DOA or damage: 2.2 devices

Run it with your numbers

  • To rerun this with your own numbers, open the live Edge Device Count calculator, set deployment uptime headroom to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.