Prepare a FAT package.
From engineering documents to a factory acceptance test, FAT package ready for vendor witness
What this covers.
Preparing a factory acceptance test, FAT package is the engineering process of assembling everything a vendor or integrator needs to demonstrate that a system, typically a PLC, a DCS, an MCC, or a packaged skid meets its specification before it ships from the vendor facility. The FAT package carries the test plan keyed to the specification, the per-tag verification matrix, the loop check sheets for I/O loops, the simulation sequence for sequence-of-events verification, and the punch-list template. FAT discipline drives the field discovery. A deficiency caught at FAT is an order of magnitude cheaper than the same deficiency caught at site.
Inputs.
- Specification, PLC functional spec, DCS HMI spec, SIS SRS, MCC schedule
- Project I/O list
- Loop diagrams
- Cause-and-effect matrix, for SIS
- Alarm rationalization, for DCS, SCADA
Outputs.
- Per-tag verification matrix, one row per I/O tag with expected, verified columns
- Per-loop check sheet template for I/O loops
- Per-SIF action verification template, for SIS scope
- Per-bucket verification sheet, for MCC scope
- Punch-list template
- Export targets. Excel workbook plus PDF binder plus JSON for the FAT-witness tool
FAT package contents by system type
| System | FAT scope focus | Per-tag verification |
|---|---|---|
| PLC | I/O point-to-point plus logic | Every I/O tag mapped to physical I/O |
| DCS | I/O plus HMI plus alarm plus sequence | Every alarm tag rationalized per ISA 18.2 |
| SIS logic solver | SIF execution plus voting | Per-SIF demand-to-action timing |
| MCC | Bucket-by-bucket plus breaker coordination | Every bucket tested for trip plus closing |
| Package skid | Functional plus interface | Every skid I/O point verified at boundary |
Step by step.
- 01Establish the I/O baselineExtract the project I/O list. Each tag becomes a row in the verification matrix. Tag-level traceability to the source P&ID page is preserved.
- 02Map I/O tags to physical I/OTags map to PLC rack-slot-channel addresses, TIA Portal Field Tag List, Rockwell I/O Configuration. The verification matrix carries the physical mapping per row.
- 03Build the loop check sheet templatesPer-loop check sheet populates with the loop topology, sensor to input to logic to output to final element. Witness fields blank for the FAT-witness to fill.
- 04Build the SIF verification, SIS scopeCause-and-effect matrix populates the per-SIF action verification. Demand simulation walks each SIF from sensor demand to final-element response.
- 05Build the alarm verification, DCS scopeISA 18.2 alarm rationalization populates the per-alarm verification. Priority distribution validation runs across the alarm set.
- 06Ship the FAT packageExcel workbook plus PDF binder plus JSON. The vendor and the owner-engineer witness the FAT against the same package.
Common questions
Does the FAT package cover MCC FAT at the builder facility.
How does this differ from SAT preparation.
Related.
Start a workspace.
Upload the source documents, run the workflow, ship the document in the column shape the next consumer expects.