It all starts with sales and marketing cramming every possible feature and half-rumour they heard about competitors' features into a 6 month project deadline. That's a long time, 6 months, no? How hard can it be? Respectfully, it'll be done when it's done.
>>dorn64+(OP)
we are the ones qualified to say what needs to be cut to provide reasonable certainty for the deadline. it is not the job of non-technical stakeholders to mitigate risk in technical projects