Nobody can know everything about an enterprise application. Some PMs have graduated from the ranks of application or technical consultants. As such, they might have the ability to answer questions about certain system-related issues. Although being able to speak intelligently about issues is hardly a liability, PMs who do not engage their teams at key points do a number of inimical things.
For one, they can alienate their consulting teams and make team members less likely to broach issues with them in the future. Second, by routinely not involving the experts, know-it-alls effectively minimize the contribution of those consultants, possibly causing clients to question the need for those consultants in the first place. Unless the consultant was specifically hired in a hybrid role of consultant/PM, that individual should routinely involve the implementation team throughout the project.
Some PMs new to projects with large scopes are ecstatic when the project makes any progress at all. Pollyannas tend to take a "glass is 10% full" approach to project management. Rather than realistically assess and deal with a project suffering from delays and budget overruns, Pollyannas focus on trying to make everyone feel good. In this sense, they are like yes-men. PMs need to be able to call a spade a spade and not worry about sugarcoating dire situations. Part of being a PM entails making tough decisions.
The pessimist is the antithesis of the Pollyanna. Pessimists fail to appreciate the gains that a team and its individuals have made in the face of considerable obstacles. Pessimists routinely overemphasize what still needs to be done as opposed to what has been done.
Make no mistake here. Many projects would benefit from healthy doses of skepticism and realism. Sometimes, it's necessary to put functionality and even entire modules on the chopping block. However, both consultants and employees tend to put in long hours on projects, especially during critical times. Few things anger a team more than unalloyed negativity from a PM not burning the midnight oil. PMs who constantly criticize a team for that which it has not accomplished are likely to irritate everyone. Celebrating a significant milestone never hurt anyone.
Sometimes PMs need to play the role of good cop, bad cop, shrink, confidant and devil's advocate. Other times, they need to stroke the egos of key people or use PM techniques to move the project forward. While there's no secret sauce to project management, avoid the archetypes described here.
This post was adapted from my first book, Why New Systems Fail.