DekEn

อัปเดต 2026-09-07

Four PHA methodologies

HAZOP · What-If · FMEA · Checklist

One worksheet engine runs four recognized hazard-study methods — HAZOP parameter×guideword deviations, free-text What-If, FMEA with a quantified Risk Priority Number, and Yes/No/N-A Checklist review — so the right method can be picked per node without leaving the tool.

เมื่อไรจึงใช้
  • HAZOP for a continuous process node with clear process parameters (flow, pressure, temperature, level).
  • What-If for a less structured review, a procedure, or a batch/operational step.
  • FMEA when failure modes need to be ranked by a numeric criticality score.
  • Checklist for a standards-compliance walk-down (e.g. a routine RAGAGEP check).
ค่าที่ต้องกรอก
ค่าคำอธิบาย
MethodologyChosen per study; fixes which columns the worksheet renders.
Guideword / failure modeHAZOP guideword (e.g. MORE, NO, REVERSE) or the FMEA failure mode being ranked.
คำนวณอย่างไร

HAZOP/What-If are qualitative deviation rows; FMEA additionally scores each failure mode by Severity × Occurrence × Detection into a Risk Priority Number, ranked against an Action-Priority table per IEC 60812.

สมการ
FMEA Risk Priority Number
S = severity, O = occurrence, D = detection (each typically 1–10). Higher RPN ⇒ higher priority for corrective action, per IEC 60812 / AIAG-VDA.
ข้อควรระวัง
noteSwitching a study's methodology after data entry re-maps the worksheet columns — free-text What-If content doesn't automatically become HAZOP parameter/guideword pairs.
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