For excavator undercarriage wear parts, how do I set replacement intervals and acceptance criteria?

• Track link pitch elongation ≥3% requires replacement.
• Replace carrier and top rollers if leaking or radial clearance >2mm.
• Sprocket tooth thickness wear ≥25% must be replaced to avoid jumping.
• During acceptance, measure link height; scrap if 15% below new.
• Set intervals by application hours: mining 1500h, earthmoving 3000h.