Did you send them this Dilbert link? Of course that can only be done if you know the guys pretty well.
My comeuppance was many years ago. A famous research hospital hinted they might need some electronics designed by me. I told them I always have other projects so I'd need to know in time when to pencil it in. "Oh yeah, we know, we'll have a few meetings and then get back to you about timing". They had meetings for the next 2-3 weeks. Then I received a request to design and organize prototyping. The request came Monday and the due date including my R&D, layout, board fab and stuffing was Thursday. I politely declined :-)
Some of my customers ask us what is the earlist possible delivery. We say something like "70 days ARO best effort". So they add 70 days to today and call that a firm commitment. 60 days later, they cut a PO and expect it in 10 days.
Or they panic and get everybody wound up and ready to make a maximum push to get something working. Then lose interest for a year. Then repeat.
The irony is that the company that does all this owns 70% of their market, and makes tons of money. Seems unfair somwhow.
I had a meeting last week wih an equipment vendor who owes us a product solution description- already a week overdue he repeated three or four times that they were on track to have it to us by the 12 th.
This is probably just a manifestation of the fact that to get work companies often need to offer unrealistic estimates, because they're competing with other companies that do, and the customer knows no better.
Throw in a bit if premature convergence due to completion pressure, and you have the recipe for a project not merely being late, but later than it would have been had a proper estimate been used.
Oh, and the expression "aggressive schedule" is code for "it'll be late, and then some."
I was talking schedules with this customer; it's a trans-gigabuck project, so I said "I sure don't want my company to wind up being the pacing item on this thing" and their manager replied, "No, no, your function is to *be* the pacing item."
OK, pay the invoices, and we'll take all the blame you want.
Agreeing to a schedule that puts you on the critical path is fine, provided you can keep to the schedule. Agreeing to a schedule that both you and the customer know you cannot possibly meet creates a risk of bad-mouthing in the wider market arena (even if 'privately'). That risks future business. I'd want a clear written statement from the customer that they know, in advance, that you will not be able to meet the 'agreed' schedule.
When I was in the USAF, one of my assignments was Beale AFB, CA, home of the SR-71 "Blackbird." (in Okinawa they called them the "Habu," an Okinawan venomous snake), and I was out with a crew of one or two other guys swapping out our box, and there was this 7-striper (I had 3 or 4 stripes at the time) who was bitching that we weren't working "fast enough." I looked him square in the eye, and asked, "Sarge, do you want it done fast or do you want it done right?"