Reference: Overview of Beyond FTP
The Script Processing Service supports the simultaneous execution of multiple scripts and ad hoc transfers. An unlimited number of scripts may run simultaneously on a Beyond FTP Server. Beyond FTP Clients process all scripts sequentially. This introduces a number of factors when designing your scripts.
Interactions between scripts must be taken into account. There can now be “collisions” between scripts that were designed to operate sequentially. In the past, these could be submitted at the same time, and the second would follow the first. Now both will run immediately. The issue is addressed with the Block_Script command that allows you to specify mutually exclusive operation.
Global resources must be available to support the increased demands of multiple scripts. You may need extra connections to meet these demands. This might also have undesired effects on bandwidth. Beyond FTP is very good and pumping data and can quickly use available bandwidth.