Ugh, this drives me absolutely mad. My work has some very defined timelines because I have 3rd parties making stuff for me. Yet the conversation about schedule

Ugh, this drives me absolutely mad. My work has some very defined timelines because I have 3rd parties making stuff for me. Yet the conversation about schedule is exactly the same every project like they don't believe me that an injection molding tool takes 6 weeks and that I need the schedule for two rounds of modifications because something unforeseen will come up.