Note
Factory Permit to Work: What to Prepare Before Arriving
A factory’s permit-to-work system belongs to the factory, runs on the factory’s schedule, and can stop your crew at the gate if the safety officer is not satisfied. Preparing for it before mobilization day is the difference between a crew that starts at 8 a.m. and one that waits until noon.
What Is a Permit to Work?
A permit to work (PTW) is a formal, time-bounded authorization issued by the factory that allows a contractor to work on or near specific systems in the facility. The factory issues it. The factory can refuse it, delay it, or revoke it if conditions change.
In Thai factory practice, PTW systems are most common when work touches electrical distribution systems, switchrooms, rooftop structures, or areas with active machinery nearby. For a solar rooftop installation or an LED retrofit across a production floor, the PTW defines which isolation points are in play, which areas are accessible, and the hours when work is permitted.
The PTW is not issued automatically when your project starts. The factory safety officer reviews your submission and decides.
What Does the Factory Need Before Issuing a Permit?
Different factories use different forms, but the information request is broadly the same:
- Scope of work: exactly what will happen, in which area, on which equipment
- Crew list: names, ID numbers, and sometimes qualification certificates for every person entering
- Isolation plan: which breakers, disconnects, or lockout points will be isolated before work begins
- Risk assessment: a brief list of hazards and the controls for each
- Equipment list: tools and materials brought onto the factory floor
- Requested work hours: the start and finish time for each day of work
For an electrical contractor doing a factory LED retrofit, this means having a crew list ready before the project starts, not on the morning you arrive. It means having an isolation drawing prepared in advance, not improvised on site.
If any item in the submission is missing or incorrect, the PTW is held while queries are resolved. Your crew waits.
How Does a Delayed PTW Affect Your Schedule?
Here is a realistic picture. The factory safety officer reviews PTW applications before the morning shift starts. Your crew arrives at 7:30. The review happens at 8:00. If the submission has a gap, the officer raises a query. You answer. They review again. Work starts at 10:30. You have lost two hours on day one.
Across a four-day LED installation job, that pattern adds up to roughly a full working day of delay spread across the project.
For a solar rooftop project, the timing problem can be sharper. The rooftop work may clear under one PTW while the electrical connection in the main switchroom needs a separate authorization, reviewed separately. The roof crew finishes their portion. The electrical crew cannot connect until the switchroom PTW is issued. The two halves of the job sit open and incomplete while the paperwork catches up.
A project that treats PTW windows as a hard scheduling constraint from the start avoids most of this.
How Do You Prepare Before Mobilization Day?
Visit the factory safety department at least three to five working days before the crew mobilizes. In that visit:
- Collect the factory’s PTW form: every facility uses its own format; get the blank form so your submission matches exactly what they expect.
- Confirm the isolation plan with the factory engineer: agree on which disconnect points will be used and who is responsible for locking them out before each work period.
- Submit the crew list and qualifications early: find out whether the factory needs to see electrical license certificates or only ID cards, and submit before the deadline.
- Ask about the review timeline: confirm how many days in advance the safety officer needs the submission, and what time on mobilization day approvals are published.
This pre-visit also confirms whether the site is genuinely ready and whether the factory contact who agreed to the project has actually briefed the safety team. Gaps found three days before mobilization are recoverable. Gaps found on mobilization morning are not.
What Do You Document Within Each PTW Window?
A PTW has an expiry time. If it covers Monday 8:00–18:00, work running past 18:00 is unauthorized unless an extension is issued. That matters for your records:
- Photograph what was completed by the end of each PTW period, with the area cleared and isolation still in place
- Note which isolation points were restored at the end of the day and re-isolated the following morning
- If a PTW window closes with work still open, record the exact state of the installation and what remains
This daily record protects you if the factory later disputes whether your work caused a fault. It also feeds the handover document directly: a commissioning record built from PTW-period notes, with photos from each window, is far more defensible than one reconstructed from memory after the job closes.
Why the Final PTW Closure Belongs in Your Handover Package
When the factory safety officer signs off on the last PTW, they confirm that all isolation points have been restored, all your equipment is off the floor, and the work area is clear. That sign-off belongs in the handover package alongside the acceptance certificate.
Factories with a rigorous safety culture will ask to see it. Without it, the handover conversation becomes harder to close, because the safety record and the project record are sitting in two different places.
FAQ
What if the factory delays the PTW and our contractual start date passes?
Keep a one-to-two day float before the contractual start date and flag any PTW delay to the project owner in writing on the day it occurs. A delay caused by the PTW review process should shift the project start date forward; it should not compress your installation window without a customer agreement. Establish that understanding before mobilization, not after.
Can the crew do anything while waiting for the PTW to clear?
Preparatory work that does not require electrical isolation, such as scaffolding or staging materials on the roof, may fall under a separate work-at-height or general access permit. Confirm with the factory safety officer what each permit covers. Do not let the crew touch panels, conduit, or wiring until the electrical PTW is in hand.
How do you store PTW records after the project closes?
Keep originals in the project file and attach scanned copies to each day’s site records. When you build the site register, include a reference to the PTW log in the commissioning documentation. Six months later on a warranty callback, you will want to show exactly what was authorized and when.
If your projects lose hours at the gate because the factory’s safety process is not ready when the crew arrives, the issue is usually that the PTW was treated as the factory’s problem rather than a task your team prepares for. Submitting the complete package several days in advance removes most of that delay.
To see how a field operations system handles scheduling and documentation around factory permits, visit /program/ or book a call.