AH Original · Case study 05

ProjSafe

Private2025Field safety · Mobile + HWS

A permit-to-work app for high-risk site jobs: risk assessments, three-step approvals and daily hazard check-outs, built in Flutter on Horizech’s HWS platform and run from a web dashboard.

Private app behind a company login. Screens are recreated with fictional sites and people.

Role: Lead Flutter developer
Stack: Flutter · HWS
Year: 2025

ProjSafe safety dashboard in the HWS workspace with job, check-in and hazard charts — hws · projsafe dashboard

ProjSafe HSE and supervisor home screens with jobs-by-status pie charts and the approve step — mobile app · iOS / Android

Type: Field safety · permit to work
Role: Lead Flutter developer
Stack: Flutter · HWS
Access: Private · behind login

01. The workflow

No permit, no work.

Hot work, confined spaces, excavation near live cables and heavy lifts all need a risk assessment and sign-off before anyone starts. On many sites that still means paper and phone calls. ProjSafe moves the whole loop onto the phone, and every step it records can be audited later.

01
Create
The worker adds the job, uploads the risk assessment PDF and picks a supervisor and HSE manager.
02
Approve
Supervisor, then HSE manager, approve or reject with a comment. A rejection sends it back for a fix.
03
Check in
Each day starts by accepting every safety check and taking site photos.
04
Check out
Each day ends with “Any hazard?” and, if so, its root cause and comments.

02. The HWS dashboard

Every site,on one screen.

ProjSafe runs on Horizech’s HWS workspace. HSE managers and admins follow live jobs, check-ins and hazards there, and manage the people, forms and equipment the app depends on.

Recreated with fictional sites and people

ProjSafe: Jobs, check-ins and hazards across every site — Jobs, check-ins and hazards across every site

03. Rules, not releases

The app reads its behaviour from the dashboard.

Which job states each role sees, under which tab, in which colour and order, comes from a status mapping on the server. Hazard assessment fields come from JSON form definitions. Change either in the dashboard and every phone picks it up on next open, with no new build in the stores.

Live counts of jobs, approvals, check-ins and hazards
Hazards grouped by the root cause reported on site
Approval trail and pre-start checks on every job
QR labels printed straight from the equipment register

ProjSafe: Every job with its team, status and risk assessment — Every job with its team, status and risk assessment

ProjSafe: Details, risk assessment and the full approval trail — Details, risk assessment and the full approval trail

ProjSafe: Tabs, states and colours each role sees — Tabs, states and colours each role sees

ProjSafe: Hazard assessment fields the app renders from JSON — Hazard assessment fields the app renders from JSON

04. The mobile app

Three roles, one app.

I led the Flutter app from its first screens to v0.1.7. After sign-in, workers, supervisors and HSE managers each land on their own home: a pie chart of their jobs by status, the jobs waiting on them, and a bottom bar with a QR scanner in the middle.

One app, three roles: worker, supervisor and HSE manager
Pie chart of jobs by status; tap a slice to load those jobs
Risk assessment PDFs uploaded and viewed in the app
Every approval, rejection and re-upload kept in the history

ProjSafe: Sign-in, worker home and today’s jobs — Sign-in, worker home and today’s jobs

ProjSafe: HSE and supervisor homes, and the approve step — HSE and supervisor homes, and the approve step

ProjSafe: New job, job details and its history — New job, job details and its history

ProjSafe: Safety checks in, hazards and root cause out — Safety checks in, hazards and root cause out

05. Field forms & equipment

Checks done where the work is.

Field Level Hazard Assessments and light-vehicle pre-trip inspections are filled in on site, step by step, then reviewed by a supervisor. Scanning the QR label on a gas detector or a crane opens its manuals, certificates and videos right there.

Multi-step forms rendered from JSON, text areas included
Light-vehicle pre-trip checks with plate, comments and review
Equipment PDFs, Office files, links and video in the app
Labels are server-side i18n keys, cached on the phone

ProjSafe: Hazard assessment, vehicle inspection and review — Hazard assessment, vehicle inspection and review

ProjSafe: QR scan, equipment library and PDF manual — QR scan, equipment library and PDF manual

ProjSafe: QR labels linked to manuals, links and media — QR labels linked to manuals, links and media

06. Architecture

A thin client, a smart backend.

The app talks to HWS through the Apiraiser client. Sessions sit in secure storage and refresh in the background, so a long shift never ends in a surprise sign-out. Status mapping and labels are cached on the phone, so screens open fast on a weak signal.

Flutter app
Worker · Supervisor · HSE
Auth
Secure storage · token refresh
HWS API
Apiraiser client
HWS dashboard
Jobs, forms & rules
Data & media
Jobs · forms · PDFs · photos

07. In numbers

First commit to v0.1.7 in seven months.

Work began in January 2025 with sign-in and the QR scanner. After the first release in July, seven more followed within a month as feedback came in from the field: hazard levels, check-out comments, vehicle number plates and a new job overview.

3: Roles in one app
88: Of 105 commits mine
8: Releases, v0.1.0 to v0.1.7
2: Platforms, one codebase

08. Technologies