You can file this under “things they forgot to teach you in business school.” Your success (and some would say survival) as a manager or business executive is directly linked to how skilled you are at managing expectations.

I’ve touched on this before, but there’s a fine art to this, and it generally takes time and practice to figure out how to do it just right. Sometimes, however, it is instructive to learn from seeing how it can go really wrong. A good example is Boeing’s inability to properly manage expectations for its new 787 Dreamliner.

In case you haven’t been following the story, the new 787 is seen as the future of the commercial airline industry. According to The Wall Street Journal, “The 787, which has received more orders than any new aircraft, is expected to save 20 percent on fuel due to a lighter-weight body and wings made mostly of composite materials, rather than aluminum.” Boeing has also done a remarkable job of marketing and selling the new jetliner. As of mid-December, the company had 762 orders for the aircraft from 52 customers, and according to the Journal, “is sold out essentially through 2014.”

In other words, the expectations for the 787 Dreamliner are extremely high, but unfortunately, Boeing has a pretty basic problem: It can’t figure out how to produce and deliver the aircraft on schedule.

“Boeing again delays Dreamliner’s debut,” said a story in USA Today. And a similar story in the Seattle Post-Intelligencer quoted Pat Shanahan, a troubleshooter Boeing brought in to manage the Dreamliner program last year after the previous program manager was fired, as saying: “If there is anything that we have learned over these past months, it is that we underestimated how long it would take to complete someone else’s work. I know our credibility is being tested on this program, and it is up to us to deliver on what we say we will do. We are committed to executing this schedule and delivering on what we have promised. We will pass this test.”

Shanahan hit the nail on the head. A manager’s credibility—and all too frequently, his job—is at stake if he can’t deliver on what he says he can do. The trick I’ve always been taught is to under-promise and over-deliver. That is, set expectations at a level where you can reasonably meet them, and then exceed them. 

This is easier said then done. Sometimes you don’t get the opportunity to set expectations. Other times, the goals and expectations get changed in midstream. And still on other occasions, people and personalities get into the mix and can foul up both the expectations and your ability to deliver them.

History is littered with great examples of unrealistic expectations being unmet. Boeing’s struggle with the 787 Dreamliner program is just the latest, and a sobering case study of why your ability to manage expectations can either take you to the next level, or send your career spiraling out of your control.