A stage gate is a rule a system enforces by refusing: the next step cannot be recorded until the step it depends on has been. A reminder is a message; a gate is a closed door. The difference matters because reminders are ignored under pressure and gates are not — when the crane is waiting, nobody reads the reminder, but nobody can dispatch a zone the system will not release. For a contractor who fabricates and installs, six gates carry most of the value: no take-off without an approved material submittal, no fabrication without an approved drawing and issued material, no dispatch without a QC pass, no inspection request before installation is complete, no handover without approved inspections, and no claim without an approved budget. The rest of this guide is that map, and how to live with it.
If the record is written and a warning follows, it was a reminder — the work proceeded and the system apologised. If the record is refused and the reason is shown, it was a gate. Most "approval workflows" fail this test: the dropdown still moves, the email goes out afterwards, and the audit trail is theatre.
A gate that a manager can switch off is also a reminder. Discipline that lives in a setting will be turned off the first week the site falls behind.
Taking off quantities from an unapproved specification means buying material the consultant may reject. The gate holds procurement until the material is approved on the record. If the site genuinely cannot wait, the bypass must be recorded as a fact — who approved verbally, when — not hidden.
The two most common ways to make scrap: cutting to a drawing that will change, and starting a zone whose material is still on a truck. The gate checks both on the zone before the first stage can be stamped.
A zone that has not passed factory inspection cannot be put on a delivery note. Rejects go back through a recorded rework round, and the gate applies again on the next attempt.
Raising a work inspection request on a half-installed zone wastes the consultant's visit and earns a rejection. The gate waits for the installed quantity to reach the zone quantity, and for the material inspection to have been approved first.
Handover is the claim's foundation. The gate requires both the material and work inspections to be approved before the zone can be closed and locked.
Invoicing before the budget is approved means claiming against numbers nobody has signed. The gate blocks claim creation until the budget is locked, and re-checks after.