STAAD.Pro Concrete Design is started by selecting the menu option from STAAD.Pro. When this is done a link file is produced that contains the basic data for creating concrete designs. This data is created each time the program is started. Additional data that is created during the use of the program is stored, such as the members, envelopes, design groups and design briefs is stored in a persistent file. This means that if the program is closed and re-opened at a later date, the data remains available and does not need to be re-entered.