As the MMC of a feature changes, the size tolerance zone also changes.

As the MMC of a feature increases, the size tolerance zone decreases, and vice versa. This is because the feature has a higher probability of being at the maximum material condition, which means it can be larger than the nominal size. Therefore, the tolerance zone needs to be smaller to accommodate this possibility. Conversely, as the MMC decreases, the feature has a higher probability of being at the minimum material condition, which means it can be smaller than the nominal size. In this case, the tolerance zone needs to be larger to ensure the feature is still within the acceptable limit.