Access to an alert method
People with access = total people × the selected access percentage. Additional people = proposed access − current access. This describes access to the selected method, not guaranteed signal coverage or an individual safety outcome.
Time before a response can begin
Scenario time = activation time + notification time + location-identification time. The model treats these as consecutive steps. Difference = current total − proposed total. A negative difference means the proposed scenario is slower. It excludes responder travel, intervention, and resolution.
Some real workflows overlap these steps. Use observed timings from your site and adjust the assumptions to avoid double counting.
Dollars saved by upgrading
Net upfront savings = full replacement total − legacy upgrade total. A negative result means the upgrade costs more; zero means equal costs. Both totals should cover the same site and functions, including equipment, installation, commissioning, removal, and applicable taxes. The upgrade total should include bridge hardware, gateways, required replacement devices, and integration work.
The starting values of $25,000 and $10,000 are editable examples, not market averages, quotes, or measured Wired4Safety savings. Ongoing subscriptions, maintenance, and future replacements are excluded from this upfront comparison. Use a separate like-for-like lifetime cost comparison for those expenses.
The compact seconds comparison
Seconds saved = current pre-response time − proposed pre-response time. Enter totals for activation, notification, and location confirmation without double-counting overlapping steps. Responder travel, intervention, and resolution are excluded.
Published retrofit evidence
Advanced reports approximately $20,000 saved compared with a new installation in a Coconino High School fire-alarm retrofit, where existing wiring was reused. This is a specific manufacturer case study, not a statistical average or a Wired4Safety LoRa deployment. Read the original case study ↗
We did not identify a representative published average for the value of existing campus alarm systems or the savings from converting DSC, Honeywell, and Napco panels to LoRa. Existing invoices, inventory, and comparable installer quotes are the appropriate starting point for your site.
From assumptions to evidence
- Inventory the people, devices, zones, and workflows in scope.
- Record the current process with representative drills.
- Define a pilot with acceptance criteria and fallback procedures.
- Measure the proposed process under comparable conditions.
- Keep limitations, failures, and unavailable results in the review.
What we do not calculate
There is no universal “percent safer” result. This model does not estimate injuries prevented, lives saved, crime reduction, regulatory compliance, or the probability of an emergency. Those claims require evidence beyond a planning calculator.
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