The bottom line: "Someone is on it" is not the same as "someone is there." Responder tracking closes the gap between claim and arrival... giving supervisors the visibility they need to know whether to wait 90 more seconds or pick up the phone and escalate right now.

The Gap Between "Claimed" and "On Site"

A claimed call with no responder visible is indistinguishable from an unclaimed call.

When a DT call is claimed on mobile, the supervisor sees "Claimed by Mike Johnson" on the shop floor display. But Mike could be 20 steps away finishing a task or 300 meters away on the far side of a large plant. Without location data, both situations look identical... and the right escalation decision is different for each.
Response time metrics are incomplete without arrival data.

Claim-to-respond time measures when a responder marked "on site" in the app, not when they physically arrived. In practice, technicians sometimes tap "Respond" when they're still in transit to avoid the system flagging them as slow. GPS arrival verification prevents this and makes response time data accurate enough to act on.
Supervisors have no basis for escalation decisions.

The right time to escalate is before a responder is needed, not after they've already been waiting for 10 minutes. Without ETA data, supervisors either over-escalate (calling the responder when they're 45 seconds away) or under-escalate (waiting 15 minutes for someone who stopped for another task and forgot to reclaim).
No audit trail for post-event accountability.

When a downtime event is investigated after the fact, knowing that a responder claimed the call but didn't arrive for 8 minutes is operationally important context. Without a timed record of claim, arrival and close, and where the call was claimed and closed from, that information exists only in people's memories... which means it typically isn't part of the root cause analysis at all.

How Responder Tracking Works

GPS tracking activates the moment a call is claimed and continues until the call is closed. No manual activation, no separate app permission request per call... tracking starts automatically when the claim is accepted.

Stage	What Happens
Call Claim	Responder GPS location is captured at the exact moment of claim. This establishes the claim-position record: where the responder was when they accepted the call. Combined with the asset's GPS coordinates, it provides the initial distance measurement.
30-Second Updates	While the call is active and unclosed, the responder's mobile app submits GPS coordinates every 30 seconds. Each update recalculates the distance to the asset and the ETA and pushes both to the boards. These updates drive the live display; they are not kept after the call closes.
ETA Calculation	ETA is inferred from the current distance and the speed of the responder's transport mode. Transport modes are administered records... walking, bike, cart... each carrying its own average speed and a percentage overhead for building layout, because a straight-line distance is not a straight-line walk. The calculation updates every 30 seconds alongside the GPS position. A responder with no transport mode set still reports a distance, because the distance is a measurement and the ETA is an inference.
Andon HUD Display	The shop floor Andon board displays responder name, current distance to the asset, and ETA in the active call row. Updates push via SignalR WebSocket... the display refreshes without page reload. Operators and supervisors watching the Andon board see live responder approach.
Respond and Close Timestamps	When the responder taps "Respond" (marking on-site) the arrival is timestamped, and when they later "Close" the call, the position is captured again. The call record holds where the call was raised, where it was claimed and where it was closed, each with its timestamp.
The Responder's Own Card	The responder sees the same picture from the other side. The active call card on the tablet names the machine they are walking to, shows how long the call has already been open, and carries their own distance out, so the person moving has the context the supervisor has.
Call Lifecycle Timings	The call record carries each step that actually happened with its timestamp and elapsed time, and leaves out the steps that never did. After the event, where the time went is a record rather than a reconstruction.
What Is Kept	Three positions per call: where it was raised, where it was claimed and where it was closed, alongside the timed lifecycle. Quality and engineering teams reviewing a downtime event can see how far the responder was at claim, how long claim to arrival took, and where the call was closed from. The 30-second updates are live only.

ProAlert asset status board showing seven machines with a colour legend for running, break, down, stopped, scheduled not running and salvaging, six of them stopped and one, a finishing cell, marked DOWN with a machine down call and a line reading that the responder is 240 metres out with an estimated arrival of 3 minutes — **Not "someone is coming". Two hundred and forty metres, three minutes.** The distance is measured from the responder's phone against the asset's own position and recalculated every thirty seconds, and the ETA is that distance divided by the travel speed configured for how they get there. Both are on the row, not buried in a detail panel, so a supervisor glancing at the board knows whether to wait or to escalate. And because the distance is shown rather than only the time derived from it, a responder who has stopped moving is visible: the minutes keep ticking, the metres do not fall.

What Is Not Collected

ProAlert tracks a response, not a person. The mobile app reads location at the moments a call changes hands and every 30 seconds while a responder holds a claimed, open call. It reads nothing between calls, on breaks, at lunch or off shift, and there is no background tracking. The call record keeps three positions... where the call was raised, claimed and closed... not a route. That is the answer for the works council, the HR review and the technician who asks whether the app is watching them: it watches the call, and only while they have one.

The Bigger the Site, the More It Matters

On a floor measured in feet, a stack light and a shout can work. On a campus measured in miles... automotive gigafactories, aerospace final assembly, shipyards... a light at the top of a staircase says only that someone, somewhere, needs help. ProAlert names the machine, names the responder who claimed the call, and puts the distance and the ETA on the board, using the phone's own GPS and the machine's stored coordinates. There are no beacons to install and no indoor positioning infrastructure to buy.

The other half of the same point is who gets told. The organizational graph delivers a call to the roles responsible for that part of the site, walking up the structure as far as the plant has configured, rather than to everyone with the app. A large site produces a lot of calls; it does not have to produce a lot of noise.

Response Accountability in Practice

82%

Reduction in response time (RHA: 22 min to <1 min avg)

30s

GPS update interval while call is active

GPS-timestamped lifecycle events per call

23,000%+

ROI on ProAlert investment at RHA Manufacturing

At RHA Manufacturing, a Toyota Tier 1 (T1) automotive stamping supplier, the combination of sub-second call delivery and responder accountability cut average response time from 22 minutes to under 1 minute. The accountability visibility that responder tracking creates... the knowledge that claim-to-arrival time is recorded and visible to supervisors on the shop floor display... changes responder behavior without requiring any policy enforcement. When people know their response path is visible, they take a more direct one.

Without Responder Tracking vs. With ProAlert

Standard Andon / Call Systems

Claim confirmed... responder location unknown
Supervisor walks floor to check response status
No ETA for escalation decisions
Response time = "Respond" button tap, not actual arrival
No record of where a call was claimed from, or how far out the responder was
Responder behavior unaffected by visibility (no accountability signal)

ProAlert Responder Tracking

Live distance and ETA on the Andon board from the moment of claim
30-second GPS updates while call is active... no supervisor walkabout
ETA-based escalation: know when to wait and when to call
GPS position at claim and at close, with the timed lifecycle between them
Claim distance, claim-to-arrival time and close position on the record for root cause and accountability review
Visibility itself improves response behavior... the Hawthorne effect, applied operationally

For IT and Plant Engineering Teams

Component	Technology	Notes
GPS Collection	.NET MAUI (Multi-platform App UI) native location API (iOS Core Location, Android Location Manager)	GPS data collected via native platform location APIs for maximum accuracy. Location permission requested at app install. Tracking activates only when a call is claimed and stops automatically at call close. No background tracking outside of active calls.
Location Storage	Call record, SQL Server	The position at initiate, claim and close is stored on the call record with its timestamp. The 30-second updates are broadcast to the boards over SignalR and are not stored. No per-person location table exists.
ETA Calculation	Server-side distance calculation, configurable walk speed	Haversine formula calculates great-circle distance between responder coordinates and asset GPS coordinates. Walk speed (m/s) is configurable per facility. ETA recalculated on each GPS update and broadcast via SignalR to Andon board clients.
Andon Board Update	SignalR push from ProAlertHub on each GPS update	ETA and distance updates delivered to all connected Andon board displays via WebSocket. No page reload or polling required. Andon board continues showing last-known ETA if GPS update is delayed.

See a live responder ETA count down on the floor display.

Book a 30-minute demo... we'll place a live DT call, claim it on mobile, and watch the distance and ETA update on the shop floor display in real time.

Schedule a Demo