This is an incompatibility conflict between two cup radius estimators with the same target and different points of view as shown in figure 7.3. It is very similar to conflicts between two selectors with the same target. The idea of a conflict between estimators makes it interesting though.
Figure 7.3: Estimate-estimate incompatibility
At some point during the design, the estimator with the stability point of
view makes an estimation using the formula 
. This estimate is not compatible with the estimate the estimator
with the handleability point of view wishes to make using the formula 
. Therefore a conflict is initiated by the
latter. The estimator with the handleability point of view asks the
estimator with the the stability point of view to give an alternate
estimate. The stability estimator produces the alternate estimation by
changing the constant coefficient in its estimation formula from 2 to 1.5.
The handleability estimator finds this alternate estimate to be compatible
with its own estimate, hence the conflict is resolved.
Here is the excerpt:
Cup Radius Stability Estimator: Cup radius estimated to be 2.0 cm. Cup Radius Handleability Estimator: Conflict detected with Cup Radius Stability Estimator. Cup Radius Handleability Estimator: Ask Cup Radius Stability Estimator for an alternative estimate. Cup Radius Stability Estimator: Using alternative estimate. Cup Radius Stability Estimator: Cup radius re-estimated to be 1.5 cm. Cup Radius Handleability Estimator: Conflict with Cup Radius Stability Estimator resolved.