In PMF 5.3.1 and earlier, you scheduled loads for each dimension and each measure, which resulted in a lot of scheduling and coordination. You had to know the data sources for each individual measure and make sure the external data from which you were loading was ready at the time each measure was scheduled. This meant you had to keep track of all these external sources, and when they got refreshed, make sure your measures always had the most recent data.
As of PMF 5.3.2, you do not need to schedule measure loads if you are using the new measure data acquisition model. The model controls scheduling in a manner that is closer to the point from which data is harvested. Measures are linked from sources, to datapoints, through the recalculation model. PMF keeps track of when data is refreshed. Schedules are only created to specify the times at which your external sources are refreshed. PMF does the rest automatically.
Currently, both the old and new models are supported. As PMF 5.3.2 moves through its hotfix cycle, legacy measures will be converted to new measures. At that point, legacy schedules will no longer be appropriate, and will return an error and schedules will need to be recreated.