Fishbone Analysis - Packaging Seal Strength

ROOT CAUSE ANALYSIS

Fishbone Analysis - Packaging Seal Strength

Seal strength below specification observed during final inspection.

CAPA-2026-0006 · Packaging seal strength below specification

Back

Interactive Ishikawa Diagram

Click any cause node to inspect evidence and root-cause status.

Cause Root cause

Cause Register

Evidence-backed causes identified during analysis

12 causes

Category	Cause	Evidence	Classification
Man	Operator did not identify early seal degradation	Interview showed seal-strength checking was performed only at the defined sampling interval.	Potential cause
Man	Shift handover did not highlight temperature drift	Handover sheet contained no abnormality note.	Potential cause
Machine	Worn thermocouple	Temperature readings differed from a reference thermometer by approximately 7 C.	Root cause
Machine	Sealing jaw contamination	Residue was visible on the jaw surface after line stoppage.	Root cause
Method	Cleaning interval not defined by production hours	Work instruction specified cleaning but did not define frequency.	Potential cause
Method	Temperature setting changed without documented verification	Parameter sheet did not require independent verification after adjustment.	Potential cause
Material	Film surface contamination	Incoming material inspection found intermittent dust particles on two rolls.	Potential cause
Material	Film thickness variation	Supplier certificate showed thickness variation within specification but close to the upper tolerance.	Potential cause
Measurement	Seal strength test interval too long	Sampling interval was 60 minutes and did not detect short-term drift quickly.	Potential cause
Measurement	Temperature sensor verification overdue	Calibration record showed verification was due within the same week.	Potential cause
Environment	High humidity near packing line	Humidity was recorded at 78 percent during the affected shift.	Potential cause
Environment	Airflow from nearby door affected cooling	Door remained open during material movement for approximately 35 minutes.	Potential cause

Add Cause

Feed the graphical analysis directly