The new Penetrations tool introduced in U10 is pretty promising. But, the current assumption that there a large 'classes' of Penetrations is flawed. There also needs to be a way to support Penetration rules/ config at Penetration level. Each Penetration should:

1. allow a rule to be assigned. Maybe even multiple Rules like the way Item Types allows multiple assignments to the individual element.

2. allow the user to switch the rule as the design is developed. Low LOD more generic rules will be progressively re-defined as more detailed as higher LOD and specific rules.

3. have a 'locked' attribute that signals to the Clash Detection run, and PM updates to bypass the Penetration objects that have this attribute set.

4. have a 'decoupled' setting. This will allow the user to modify the Penetration object but still use the PM to flag any changes to both the cutting and cut parent elements.

5. have a 'recouple' tool that will allow the user to re-couple the Penetration object to the PM and Clash Detection runs. This combined with the object level rules will allow the user to say slave the positioning of the Penetration to the cutting/cut objects, but allow the user to manually define the size/extent.