IIoT, SCADA & Edge Connectivity worked example

Dashboard Refresh Latency at 71% analytics and historian server uptime: a worked example

This worked example runs the dashboard refresh latency numbers for a tougher week than the baseline: 71% analytics and historian server uptime instead of the typical 99%. Estimate concurrent dashboard refresh capacity from dashboards refreshed per server thread per minute, planned refresh minutes in the period, server uptime, and the share of refreshes that complete inside the latency SLA.

The inputs for this scenario

  • Dashboards refreshed per polling thread per minute: 10 dashboards / min (held at the documented default)
  • Planned refresh window in the period: 480 min (held at the documented default)
  • Analytics / historian server uptime: 71 % (the input this scenario stresses; the baseline uses 99)
  • Refreshes completing inside SLA: 95 % (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Gross dashboard refresh capacity = dashboards per minute × planned minutes.
  • Dashboards delivered inside SLA works out to 3,238 dashboards at these inputs, and this is the headline figure for the scenario.
  • Gross dashboard refresh capacity works out to 4,800 dashboards at these inputs.
  • Server downtime loss works out to 1,392 dashboards at these inputs.
  • SLA miss loss works out to 170 dashboards at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where analytics and historian server uptime sits at 99% and the headline result is 4,514 dashboards, this scenario comes in 28.28% below the baseline at 3,238 dashboards.
  • Use it when sizing a Grafana/Ignition/PI Vision dashboard tier, validating a refresh SLA before sign-off, or diagnosing why operators report stale tiles during a shift. A result at this level usually justifies acting on the stressed input before touching anything else, because every other figure in the table is downstream of it.

Results at a glance

  • Dashboards delivered inside SLA: 3,238 dashboards (headline result)
  • Gross dashboard refresh capacity: 4,800 dashboards
  • Server downtime loss: 1,392 dashboards
  • SLA miss loss: 170 dashboards

Run it with your numbers

  • To rerun this with your own numbers, open the live Dashboard Refresh Latency calculator, set analytics and historian server uptime to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.