About Plus and Minus Tolerancing

When using only plus and minus tolerancing schemes (no geometric tolerances), there are several cases that prevent a part from being fully constrained. The most common cases are when you create features on common centerlines and axes, meaning that the distance between features is zero.

Examples

In this part, there are no dimensions or tolerances controlling the coaxiality of the 12.3 and 50 diameters, and no dimensions or tolerances controlling the vertical offset between the 12.3 diameter hole and 8.5 wide notch. In this part, there are no dimensions or tolerances controlling the coaxiality of the three diameters.
When you click Show Tolerance Status , several features are under constrained (in yellow).
If you apply these tolerances schemes, all features are fully constrained.