Select this option to calculate the remaining life of a component based on a minimum required thickness for the intended service conditions, thickness measurements from an inspection, and an estimate of the anticipated corrosion rate. This method is acceptable for calculating the remaining life for Type A Components (see paragraph 4.2.5). Because the thickness-based approach (this option) might produce non-conservative results for the remaining life when applied to Type B, Class 1 Components (see paragraph 4.2.5), you need to use the MAWP Approach for those components.