Technical
Barış Ertekin · Commissioning Manager
In most specs the acceptance test is two lines: FAT and SAT. Purchasing reads them as calendar milestones. On the floor they are different locks. One closes the scenario; the other closes tempo and habit.
The mix-up is expensive. I/O that went green at FAT breaks the operator’s reset sequence at SAT. A line that ran at SAT turns into an alarm flood on the night shift.
Handover does not close with the sentence “it runs.” A connected cell is not a finished job.
Two lines, two different locks
FAT is acceptance of the controlled environment. SAT is acceptance of the line. Crushing both on the same day, with the same checklist, pushes the open item to the next shift.
If scope is locked from the start, the two gates stand clear. If scope is open, FAT is “passed” and SAT is “almost.” The handover argument starts there.
What FAT locks
FAT is done in a controlled environment. Cabinet, software, and where possible the cell are not yet at production tempo. The aim is to show that the included scenarios match the I/O list.
Scenario and I/O
A missing interlock, a missing recipe, a wrong safety sequence is caught here. A green lamp is not evidence if there is no scenario.
- I/O and safety sequence run one-to-one with the written scenario.
- HMI labels, alarm classes, and the reset step are read.
- Missing items, or items left as “we’ll see on site,” are written into the record.
What FAT does not claim
Production count, shift rhythm, and operator habit are not FAT’s job. Trying to lock them at FAT empties SAT.
What SAT locks
SAT is done with the part, the operator, and the adjacent station. Cycle, cleaning window, gate opening, and the real buffer show here.
If the robot holds its own cycle and the line is still waiting, SAT does not close. Transfer is not locked on the table.
Part family
A SAT that passes on a single reference drops when the recipe changes. Acceptance is done with the family that was discussed. If a variant outside the family is “we’ll see later,” it stays open on the record.
Reset and gate
If the sequence the operator knows conflicts with the sequence on the drawing, the HMI changes. This is not a training note. It is an acceptance item.
First shift
SAT day can be quiet. A night-shift alarm is not left as “your job” after handover. The first stops are read together.
A connected cell is not a finished job. I/O list, line rhythm, and operator habit close on the floor.
When handover closes
The handover record is signed when no open item remains. Tags and HMI stay in a language the night shift can also read. Support is not an annex to the record; it is part of handover.
- FAT open items are closed, or have been moved to SAT on purpose.
- SAT has run with the discussed part family and reset sequence.
- The first-shift watch window is written on the record.
Locking scope from the start stops FAT and SAT from being calendar decoration. In the process these two gates stand apart: controlled first, then tempo.
