Professional Planners are essential to any complex project where detailed plans are required but I experienced a wide range of ability
Most were good at setting up an initial plan, using impressive software packages, but quite a few did not use it effectively during the project
The best project planners were those who stuck to reporting against the baseline plan, actively engaged with people on the project and bravely forecasted the way forward. So giving project and contract managers the data needed to make decisions
Not historians who were forever updating the base plan (so always on schedule!) and blaming subcontractors for not giving them data to update plans (little proactiveness or ownership)
