Several factors affect space utilization in a PDSE. Compared to a PDS, there are both advantages and disadvantages in how a PDSE uses space. However, when considering the space differences, remember that a PDSE has the following functional advantages. A PDSE does not need to be compressed, it has an expandable directory so that space planning is less critical, and it can be shared more efficiently.

The following are some areas to consider when determining the space requirements for a PDSE.