A popular reality TV show is "Dancing with the Stars" in which celebrities are partnered with a professional dancer and perform set dances each week. Depending on the ability, or otherwise, of the celebrity then the professional does more or less work. The flash comes from the 'Pro', the celebrity just has to stay upright! Recently I've come across a business version, real reality in fact. It could be called "Dancing with the PM!"
In this example the management decided that they would implement an application that they had no experience with, they would ask the already overworked members of the department to write the business requirements, they would give them five months to implement the application. The department manager then decided to make one of his staff the tech lead although he'd never managed any tech work before and the contract developers he's managing would be working remotely - 2000 miles and three time zones away.
Now this is we're the "Dancing with the PM" happens. Six weeks into the 20-week project they decide that they need an experienced PM to "help" with the project. He's also in the "New guy" stage of his employment.
I think you can guess the outcome. A team experienced in the particular application would have been hard pressed to make the planned date, this group of novices had no chance. Putting a famous classical conductor - Simon Rattle, Loren Maazel, Georg Solti - with an elementary school band is not going to guarantee great music.
The outcome was that the project missed its delivery date by an additional 16 weeks, the PM did however avoid the fall out, and the department manager did not! Now that was a surprise. Usually we take the fall. So the lesson from this example is that when you take over a project carry out a quick, but thorough, appraisal of your resources, communicate your findings/concerns, and make the necessary adjustments to the project plan.