When do new faction warfare plexes spawn?

With the recent Crucible expansion CCP changed the spawning mechanics of the faction warfare plexes, allowing them to spawn more often. Capturing as many plexes as possible is essential for switching occupancy of a system, so understanding which factors affect plex respawning could help to maximize the number of plexes available.

I've heard conflicting information about whether players inside a captured plex can block the spawning of further plexes.

I'm curious about the following aspects of plex spawning:

• How often do new plexes spawn?
• What factors prevent new plexes from spawning?

Solution 1:

According to a source I found new faction warfare plexes spawn every thirty minutes.