Keep cost knowledge separateKnown facts: Available design data; Assumptions: Clearly stated scenario; Unknowns: No invented prices; Review milestone: Replace old allowance. An unknown amount is not zero.Keep cost knowledge separate01Known factsAvailable design data02AssumptionsClearly stated scenario03UnknownsNo invented prices04Review milestoneReplace old allowanceAn unknown amount is not zero.³Ô¹Ïtv • explanatory diagram, not a production or inspection record