Front-End Engineering Design.
FEED is where the controls scope first becomes a number on a budget. The P&IDs are preliminary, the equipment list shifts weekly, and the I/O count drives PLC sizing, cabinet count, and DCS license cost before any of it is locked.
Three drawings included on a new account.
P&ID extraction at FEED phase.
FEED phase documents from preliminary P&IDs. I/O count for PLC sizing, BPCS and SIS scope split, equipment list for long-lead procurement, revision-aware.
What FEED produces.
- Preliminary I/O count for PLC and DCS sizing
- Major equipment list keyed to long-lead procurement
- Preliminary instrument index with tag-area allocation
- Line list scaffold with major process line spec breaks
- BPCS, SIS scope split for license and architecture sizing
- Cost class estimate, typically Class 3, AACE 30
Where Tagsight fits.
- Reads partial P&IDs and produces an I/O list at the density the drawing carries today, without requiring drawings to be final
- Re-runs the same drawing set as revisions land, producing a comparison report so the I/O count delta is visible per revision
- Outputs a separate BPCS and SIS scope split so PLC and safety controller sizing can be priced independently
- Equipment list extraction feeds the procurement long-lead list directly
- Exports to Excel and CSV for estimating teams. Structured JSON for downstream estimating tools
- Holds revision history per workspace so the FEED-to-detail handoff carries the full extraction lineage
Common challenges.
- I/O count grows 15-30% from FEED to issued-for-construction. Teams that never re-baseline blow the marshalling cabinet allocation
- BPCS and SIS are often blended on early drawings. Separating the SIS tags is required to size the safety controller and license LOPA outputs
- Hand-counting from preliminary P&IDs takes the same effort as hand-counting from final P&IDs but yields a number that ages out in two weeks
- Equipment lists drafted in spreadsheets diverge from the P&ID equipment as drawings revise, leaving the procurement schedule built on stale data
- Cross-discipline handoff. Process engineers own the P&IDs, electrical owns the cable count derived from I/O, controls owns the PLC sizing, and all three need the same numbers from the same source
- FEED estimates have to defend their numbers to a third-party reviewer. A structured extraction with provenance per tag is easier to audit than a hand count
Common questions
Can Tagsight extract from drawings that are still marked Issued for Review.
Yes. Tagsight reads what is on the drawing today regardless of revision status. The output carries a revision identifier per workspace so you can compare FEED Rev A against FEED Rev B and see the I/O delta.
How does the FEED I/O count carry forward into detail engineering.
The same workspace continues into detail engineering. Each issued revision produces a new extraction run, and the comparison report shows added, removed, and modified tags between revisions. The detail engineering team inherits the FEED baseline rather than starting from a fresh transcription.
Does Tagsight handle the BPCS, SIS scope split required for safety controller sizing.
Yes. The extracted dataset carries signal class, and SIS instruments stay distinguishable from BPCS, so the SIS list can be issued on its own for the safety controller bid package.
What if the FEED P&IDs are scanned PDFs rather than CAD-native.
Both work. Whether a sheet is a CAD-native PDF or a scan, the structured output is the same. Image quality is what varies, not the format.
Use it through FEED.
The I/O count from FEED drives the Class 3 estimate, the PLC and DCS license selection, and the marshalling cabinet count. Get that number off the actual drawing set with the BPCS and SIS scope separated, before the estimate is presented to the approval board.
Three drawings included on a new account.