Working offline

What the handset holds, how queued work reaches the server, what the four sync words mean, and what happens when two people change the same job.

The field app assumes there is no network. Everything else follows from that.

What is on the handset

An encrypted copy of the work assigned to you, the assets it concerns, and the lists needed to fill a job in. Not the whole plant — what you need for your work.

The database is encrypted with a key derived from your passcode, and the key exists only while the app is open.

How a change travels

1. You press a button. The screen changes immediately.
2. The change goes into the outbox.
3. When there is signal, the outbox is sent in the order things happened.
4. The server accepts, refuses, or reports a collision.
5. The chip on the job updates.

The four words

The Sync screen exists so these are sentences rather than colours.

Word	Meaning	Do you need to do anything?
Pending	Waiting for signal	No. It goes on its own
Applied	The server has it	No
Failed	The server refused it, with a reason	Read the reason
Conflict	Somebody else changed the same job	Yes — a person must decide

Failed operations

A failure carries the server’s own error code and message. It took trouble to say why, and “sync error” would throw that away.

Common causes: the job moved to a state that no longer allows what you did; a part was consumed elsewhere; your permission changed.

Conflicts

A conflict is not a failure. It means two people did something to the same job and the system will not guess which is right.

Conflicts are not resolved on the handset. Deciding needs both versions side by side, and pretending to resolve one on a phone without showing both would be exactly the silent overwrite the design exists to prevent.

They are resolved in the main app’s Sync Center. What the handset does is tell you one exists, so it does not sit unnoticed.

Where nothing material actually collided — two changes that do not touch the same fields — the system resolves it by rule and tells you it did.

Photographs

Evidence travels on its own road, separately from the queue of status changes. A large photograph on a weak connection does not hold up the completion behind it.

What to do at the end of a shift

Get within signal and open Sync. If everything says applied, you are done. If something says pending, leave the app open a moment. If something says failed or conflict, tell your supervisor — those need a person.

Do not wipe a handset that still has pending work. That work has not reached the server, and wiping is the one action that loses it.