At the start of a project, when we know the least, assume the best, and are often pressured to deliver, is the worst time to define long term timelines. Anchoring on the optimistic future despite a glaring absence of future evidence.
“Anchoring is another type of cognitive bias that plays a big role in the planning fallacy.”
https://thedecisionlab.com/biases/planning-fallacy
https://thedecisionlab.com/biases/planning-fallacy