their window—a small slip resulting in a slip of six months or more—caused some disappointments, but the proactive communication of the consequences eliminated the surprise factor.
Another client had a parting of ways with a systems integration firm partway through a project and needed to quickly find a new firm and restart the effort. In order to avoid the significant schedule delay that would normally be associated with this setback, they reduced the scope of their effort significantly, stripping out all optional functionality for the first release to reduce the complexity (and risk) of the project for their new vendor.
Proactively identifying risk and then acting to assure that risks are mitigated, monitored, and effectively communicated is what project management is all about. This doesn’t guarantee that there won’t be surprises, it just decreases the likelihood that they will be of the unpleasant, “How could you not see this coming?” variety. This helps conserve energy and sympathy for the inevitable surprises that the future holds.