Fixed dates above, elastic work below, weighted load at the bottom. Bar thickness is weighted hours per week; bar length is the window it sits in, not time occupied.
load = allocated hours × mode multiplier × deadline pressure. Allocation splits each week\u2019s available hours by priority. Push these around: if the load curve barely changes shape, the model is robust and the exact numbers don't matter. If it swings wildly, the weighting isn't carrying information and the honest move is to drop it for plain concurrency.