Concepts

Concept pages explain why TuffOps works the way it does. Read these once to build a mental model, then come back when something surprises you.

If you need to do something specific, Guides is the better starting point.

Foundations

Data Model — the entities (customers, units, work orders, quotations, invoices, customer requests, checklists) and how they connect.
Settings & Feature Flags — tenant keys in the settings table, feature gates, and what is readonly vs editable in Settings.
Permissions Model — area.action keys, typical role profiles, and how to design custom roles safely.

Customers — the three customer types, how names work, contact info, and integration with external systems.
Units — equipment records, the warranty clock, maintenance frequency, and linked groups.
QR Codes & Public Unit URLs — what's on the public page, what isn't, and the scan-to-request-service flow.

Quotation Lifecycle — why submitted quotations lock, what each status means, and how a quote becomes work orders.
Work Order Lifecycle — every status, every transition, who can move between them.
Customer Requests — what a request is, how it differs from a work order, and the triage flow.
Invoices — the three statuses, the feature flag, and external billing integration.
Checklists — auto-attach precedence, snapshots, frequency, manufacturer scoping.

EPA Part 84 — AIM Act tracking: charge events, leak inspections, mothball, RLCA carve-out, chronic-leaker classification.
Compliance Overrides — the three override kinds, gating modes, four-eyes rule, and the audit row each decision writes.
Leak-Repair Episodes — from a red leak-rate calc to a closed §82.157(c) episode, including verifications, extensions, and the next-add presumption.
Chronic-Leaker Classification — the §84.106(j) 125% calendar-year rule, the eligibility floor, and the active → reported → withdrawn lifecycle.

Technician Permissions — what the technician role grants and what's reserved, gate by gate.
Work Orders from a Tech's Perspective — the pending-start gate, the items card, the status widget, and what's hidden vs. disabled.
Mobile and Field Context — TuffOps on a phone or tablet, GPS and camera permissions, and the offline story.

You're trying to...	Start with
Onboard onto TuffOps	Data Model
Find a feature flag or tenant default	Settings & Feature Flags
Grant access to a new staff member	Manage Users
Understand why a button doesn't appear	Permissions Model
Figure out why a quotation can't be edited	Quotation Lifecycle
Figure out why a work order can't move to a status	Work Order Lifecycle
Set up checklists for the first time	Checklists
Trace EPA Part 84 obligations	EPA Part 84