IIoT, SCADA & Edge Connectivity calculator

SCADA Screen Utilization Calculator

Estimate SCADA screen utilization. Enter the count of distinct screens opened by operators in the last period, the total screens deployed in the SCADA, and the use-rate target. The calculator returns the use rate and the gap to target.

What this calculator does

  • Estimate the share of SCADA HMI screens actually used by operators from the count of screens opened in the last period against the total screens deployed, against a use-rate target for the rationalization plan.
  • Use it when an HMI design or operations lead is checking which SCADA screens are actually being opened by operators, before pruning unused screens during a screen rationalization or HMI redesign.
  • It returns the share of SCADA screens actually opened by operators in the period and the gap to the rationalization target.

Formula used

  • SCADA screen use rate = screens opened ÷ total deployed screens × 100
  • Use-rate gap to target = target use rate - actual use rate (negative gap means below target)

Inputs explained

  • Screens opened by operators in the period: Use the count of distinct SCADA HMI screens opened by any operator in the audit window (week, month, or quarter).
  • Total deployed SCADA screens: Use the count of HMI screens currently deployed in the SCADA project, not historical or template screens.
  • Screen use-rate target: Use the target from the rationalization plan (typical 70 to 85 percent within ISA-101 designs; below 50 percent indicates a lot of dead screens to retire).

How to use the result

  • Use it before an ISA-101 HMI redesign, before pruning unused screens during a SCADA migration, or in an HMI design review.
  • It tells you screens are unused, not why. Some screens are kept for emergency or audit; tag them as exempt before pruning.

Common questions

  • How long an audit window should I use? One month is a good default for production screens. Use a quarter for screens used during start-ups, shutdowns, or quarterly cleans.
  • Why is my target below 100 percent? Plants keep some screens for emergencies, regulator audits, or rare maintenance modes. A target of 70 to 85 percent leaves headroom for that.
  • How is this different from operator dashboard adoption? Screen utilization measures any operator opening any SCADA screen. Dashboard adoption (separate calculator) measures how many distinct users use a built-for-purpose dashboard regularly.
  • Should I retire every unused screen? No. Tag exemptions for emergency, regulator, or rare-mode screens. Retire the rest after the next operations review signs off.

Last reviewed 2026-05-12.