Multiple-project hierarchical planning is a powerful and robust approach to solve the global system planning problem. This proposal is based on a decomposition-aggregation structure of projects and resources having multiple levels, where the higher levels contain more aggregated data with longer time horizons, while the lower levels contain more detailed data and shorter time horizons. Each level has a model composed by entities and attributes, and a decision making problem. The difference between this approach and the single-level architecture is that in the former not only are all levels used for making decisions within the same level, but they are also used for making inherited decisions from higher levels, generating a continuous feedback process. Additionally, under the hierarchical planning approach, the load-capacity analysis looks for improving the offer and demand of resources so that the specified due dates can be satisfied. This analysis is implemented by measuring some indicators that reflect the state of the load/capacity relationships, and by executing a leveling procedure to achieve the load/capacity balance. We have performed several experiments using a set of randomly-generated projects and obtained good results.