Context
Issuing a Work Permit (PT) on complex sites involves up to eight signatures, safety checklists, photo attachments and paper-based validation. On big sites, this stalls activities for hours every day.
The challenge: digitize the entire process in an app that worked offline, on the worker’s phone, in open field with poor signal.
Field research
I spent five days on site shadowing real permit issuances with supervisors, safety engineers, and workers. I mapped 23 moments of friction — from “I lost the paper” to “no signal in the tunnel”.
Key insights:
- Reading time is critical. Workers skim — screens need aggressive hierarchy.
- Photos are the document. More useful than digital signatures, since they prove physical state.
- Offline-first is non-negotiable. Signal drops 30% of the time on site.
Design
I structured the flow in three states: draft, under review and approved. Each state has a specific background color and icon, readable even under direct sunlight.
Photo signature. Instead of digital signatures (which nobody validated legally), the app captures a photo of the worker with PPE on site. Solves auditing and doubles as proof of presence.
Adaptive checklist. The app assembles the checklist based on activity type (work at height, confined space, hot work). We reduced average fields from 47 to 18.
Outcome
- 78% reduction in average issue time (from 42 min to 9 min).
- Zero paper in three pilot sites after two months.
- +5,000 permits issued in the first half.
The app is now part of GAP’s standard offering contract.