Steps for prep. of schedule

1.) Define the WBS. One might argue that this is not needed as the same results can be gotten from a well defined activity coding structure. A well defined WBS helps in the though process of developing the project and every project will require a unique WBS as no two projects are the same unless you are duplicating a project. A WBS must always roll up to the finished product.
2.) decide on activity coding. Some will be already defined as ’Global’ others will need to be developed specifically for the reporting needs of the project.
3.) Define the calendars needed for your project.
4.) Identify resources needed for the project.
5.) Involve as many people associated with the project to formulate a project strategy and revolve the project plan around this philosiphy.
6.) Ensure you set all the correct parameters within Primavera before you start working on your project activities like the default hours in a day, fixed durations and units, etc.
7.) Now jump in and develop a schedule.

the key is to involve as many people as you can in the thought process during the development stage of the project schedule and not develop the schedule in isolation.