When such crucial conversations don't occur, he said, projects suffer. According to Maxfield, 74 percent come in over budget, 82 percent miss deadlines, 79 percent fail to meet quality or functional specifications, and 67 percent result in damaged team morale.

A comprehensive report on the data will be released in September, but Maxfield said preliminary results indicate an overwhelming need for project managers to "speak truth to power" as well as for corporate leaders to make it safe for that to happen.

Leaders, he said, need to create a culture where crucial conversations are consistently held, and they must measure their progress in creating such a culture as a leading indicator of project success.

Meanwhile, individual project managers can make an immediate difference by increasing their competence at initiating and holding these crucial conversations, Maxfield said. "When you speak up, you make it safer for everyone around you to speak up; and when you don't speak up, you make it harder for everyone around you to speak up," he said.

Because these situations tend to reflect patterns of process violations, he said, project managers who can confront and resolve them "get incredible leverage for improvement."