Cost Estimate by Design Phase (Conflicting Ballast & Black Spectacles)

Hi, 

I received a question on a Black Spectacles practice exam which stated that an 'Assembly and Systems' estimate should be used during the Design Development phase. According to my notes below from reading Ballast, the ARE 4.0 Review Manual and AHPP, an Assembly and Systems estimate should be used in the Schematic Design phase, NOT DD. Any clarification would be appreciated. 

New Project Feasibility = Project Comparison Method based on similar (area, cost per bed, etc.) 15-25% accurate 

Preliminary Design = Area or volume method (school has classroom, lab, etc. all w/ different cost per SF) 5-15% accurate 

Schematic Design = Assembly or Systems estimate  (gen config., space req., subsystems can be compared) 

DD/early CD = Parameter Method (itemized quantities & unit costs for each type, helps eval. VE) 

CD's & Specs Done = Unit Cost Method most accurate, breaks down individual building components & labor to install, includes, material, labor, OH&P, sub work, fees, FF&E