VnV – avikr.com

Potential Effect(s) of Failure	Severity (S)	Potential Cause(s)	Occurrence (O)	Current Design Controls	Detection (D)	RPN	Recommended Action
Reduced lumen diameter, restenosis	9	Insufficient radial strength	4	Radial compression testing, FEM analysis	4	144	Optimize strut geometry and material properties
Vessel injury, malapposition	8	Uneven balloon expansion or poor design	5	Balloon expansion simulation, bench testing	5	200	Improve expansion symmetry and balloon compatibility
Embolism, restenosis, device failure	10	Cyclic arterial loading	3	Fatigue simulation and durability testing	4	120	Improve fatigue-resistant design and material selection
Thrombosis, restenosis	9	Poor surface finish or material incompatibility	3	Biocompatibility testing per ISO 10993	3	81	Improve coating and surface treatment
Procedure failure, vessel trauma	7	Excessive stiffness	5	Trackability and flexibility testing	4	140	Reduce profile and improve flexibility
Improper deployment	8	High crimping stress	4	Crimping simulation and dimensional inspection	4	128	Optimize crimping parameters and strut thickness
Acute thrombosis	10	Inadequate coating or rough surface	2	Hemocompatibility testing	4	80	Enhance anti-thrombotic coating
Vessel blockage or inadequate treatment	9	Improper sizing or poor anchoring	3	Deployment testing and imaging analysis	5	135	Improve anchoring and sizing guidance
Restenosis or toxicity	8	Coating inconsistency	4	Drug release characterization	4	128	Improve coating uniformity process
Structural degradation	8	Aggressive physiological environment	2	Corrosion testing	3	48	Use corrosion-resistant alloys or polymers

Process Step	Potential Failure Mode	Potential Effect(s)	Potential Cause(s)	Prevention Controls	Detection Controls	S	O	D	RPN	Recommended Actions
Material Receiving & Inspection	Incoming material out of specification	Compromised stent mechanical properties, coating failure, patient injury	Supplier variation, inadequate incoming inspection	Approved supplier list, CoC verification	Incoming dimensional and material inspection	9	3	3	81	Strengthen supplier audits and incoming testing
Laser Cutting (Stent Patterning)	Incorrect strut geometry	Poor radial strength, restenosis, thrombosis	Laser misalignment, programming error	Validated laser parameters, preventive maintenance	Vision inspection, dimensional inspection	8	4	4	128	Real-time monitoring and tighter process controls
Electropolishing	Over/under polishing	Reduced fatigue life, particulate generation	Incorrect voltage/time, electrolyte variation	Process parameter validation	Surface finish and dimensional checks	7	4	4	112	Automate parameter control and trend monitoring
Cleaning	Residual particulates or contaminants	Coating defects, thrombogenic risk	Insufficient cleaning cycle, bath contamination	Validated cleaning procedure	Particulate and TOC monitoring	8	3	4	96	Increase particulate testing frequency
Coating Application (Drug & Polymer)	Coating thickness out of specification	Under/over dosing, coating delamination	Viscosity variation, dip speed variation	Validated coating process	Coating thickness measurement	8	4	4	128	Inline viscosity monitoring and automation
Drying & Curing	Incomplete drying/curing	Poor adhesion, particulate formation	Incorrect temperature/time	Oven cycle validation	Temperature monitoring and adhesion testing	7	3	4	84	Improve oven alarms and adhesion testing
Crimping & Mounting	Stent deformation/fracture	Acute closure, compromised deployment	Excessive crimping force, mandrel damage	Validated crimping process	Post-crimp visual inspection	9	3	3	81	Vision-based strut integrity inspection
Sterilization	Sterilization dose out of specification	Infection risk, material degradation	Incorrect cycle parameters	Validated sterilization cycle	Dosimetry and release testing	9	2	3	54	Routine calibration and preventive maintenance
Final Inspection & Packaging	Seal failure or labeling error	Loss of sterility, wrong product use	Human error, sealing parameter variation	Validated sealing process	Seal integrity and label verification	8	3	3	72	Increase label verification and seal testing