When I was a young programmer in the early nineties, an old IBM programmer told me 'Don't accept the invitation to fail.' Good advice but what if the goal posts

When I was a young programmer in the early nineties, an old IBM programmer told me 'Don't accept the invitation to fail.' Good advice but what if the goal posts are moved. Best then to keep positive and communicate early and often about how the changes will affect the schedule. Work together as a team and get your manager to help you and that'll go a long way rather than keeping 'obvious' things to yourself and catching management off guard when work slips.