Functional Logic Diagrams — Final Self-Verification Checklist

Header & Document Control

• Title states “Functional Logic Diagram” with function/loop ID, unit/area, and sheet X of Y; drawing/document numbers follow project standard.
• Revision index & purpose (IFR/IFA/IFC/IFD) correct; prepared/checked/approved names and dates completed; change log maintained.
• References listed with numbers & revs (P&IDs, Control/Safeguarding Philosophy, Control Narrative/Sequence, C&E Matrix, Alarm/Trip Schedule, I/O List, Instrument Index, System Architecture, Vendor PLC docs, Client standards).

Scope & Basis of Design

• Functional boundary defined (what starts/stops/controls/trips) including interfaces and exclusions; assumptions explicitly noted.
• Applicable standards identified (e.g., ISA 5.2/5.06, IEC 61131-3 notation, IEC 61511 guidance for SIS); client DCS/PLC coding & HMI style guides applied.

Function Overview & Modes

• Context diagram shows main inputs/outputs, external systems, and feedbacks; state diagram (where used) matches narrative.
• Operating modes listed (Auto/Manual/Cascade/Local/Remote) with transfer rules, interlocks per mode, and bumpless transfer/track-&-hold behavior.

Inputs & Signal Conditioning

• All inputs listed with tag/description/type (AI/AO/DI/DO/RTD/TC/pulse), normal range & ENG units; scaling, filtering, clamping and status (quality/bad PV) handling defined.
• Loss-of-signal/comms rules documented (freeze, substitute, safe default); manual substitute authority & audit trail requirements noted.

Setpoints, Limits & Calculations

• SP source defined (operator/recipe/APC/remote) with security level; min/max/engineering limits enforced; units/decimals consistent with Alarm & Trip Schedule.
• Hysteresis/deadband, rate & slew limits, bias/gain or linearization documented; calculation blocks (averages, selectors, summer/split range) shown and referenced.

Interlocks, Permissives & Voting

• Boolean expressions/truth tables match narrative; permissives & inhibits enumerated with AND/OR logic and reset paths; seal-in/latch behavior clear.
• Voting schemes (1oo2, 2oo3, cross-zone) defined where used; diagnostics/fault voting rules stated; independence/separation maintained for SIS functions.

Sequences (Start/Stop/Purge/Restart)

• Step list shows preconditions, actions, outputs, step-complete/abort conditions; handshakes with packages/MCC (Ready/Start/Run/Trip/Ack) defined.
• Timers, retries, purges, delays, and inter-step timeouts specified; cold/warm restart behavior and step resume rules documented.

Alarms, Priorities & HMI

• Alarm points listed with priority, type (process/equipment/safety), latching/reset policy, delays, and shelving/inhibit rules; ties to Alarm & Trip Schedule correct.
• HMI/SCADA objects referenced (faceplates, permissive/interlock summary, sequence overview); messages clear, action-oriented and unit-consistent; SOE/time-stamp source stated.

Outputs & Final Elements

• DO/AO mapping correct with energize-to-run/trip policy; fail-safe states defined; interposing relays/solenoids/feedbacks shown; manual reset paths identified.
• Overrides/PST/test outputs safeguarded (time-limited, authority, indication); maintenance mode behavior and return-to-service rules clear.

Bypass, Override & Force Management

• Bypass/override/force points identified with authorization level, timeout/auto re-enable, SOE logging, and alarm/graphic indication requirements.
• Degraded mode rules defined (max allowed bypasses, restricted operation, additional alarms); recovery procedure documented.

Safety & SIS (if applicable)

• SIF IDs and targets referenced to SRS; separation/independence from BPCS stated; safe state on detected faults and fault-tolerant behavior documented.
• Proof test/override notes included where logic affects SIF; trip initiators/voting consistent with C&E; demand/response time budget noted if specified.

Interfaces & External Systems

• Handshakes with ESD/SIS, F&G, package PLCs, MCC/VSD, analyzers and utilities shown; comms type (hardwired/serial/Ethernet) and loss-of-comms behavior defined.
• Cause/Effect outputs cross-referenced to clause IDs; permissives from electrical/protective devices correctly represented with status feedbacks.

Testing, Simulation & Acceptance

• Test cases enumerate normal/abnormal scenarios with expected results; simulation/forcing points identified; FAT/SAT/loop-check references included.
• SOE/time sync source defined; response time/alarm performance verification plan documented; rollback/restore strategy for logic changes noted.

Graphics, Notation & CAD Quality

• Symbols/notation per client/ISA; connectors and page links resolve; layering, text sizes and lineweights legible; no overlaps or clipped text; sheet index complete.
• Hyperlinks/callouts valid (to C&E, Alarm/Trip, I/O List, P&ID, vendor docs); PDFs export with selectable text; print areas/page breaks set.

Data Integrity & Final Polish

• Consistency scan vs P&IDs, Control Narrative, C&E Matrix, Alarm/Trip Schedule, I/O List, Instrument Index and Interlock List; no duplicates/orphans.
• Mandatory fields complete; units/abbreviations consistent; grammar/notes tidy; confidentiality/footer correct; transmittal list aligned.