First of all, you may notice that the event popularly known as "The Rapture" isn't on it.
Well, it is and it isn't.
When I read these verses a little more closely I realized a few things. First, vs. 14 indicates that those which "sleep in Jesus" (i.e. are already dead to this world and living their life after life) will be brought with Jesus when he comes.
Second, the following verses makes it clear that those who are alive at this time will not precede those which are asleep when it comes to joining Jesus in the air. The dead in Christ will rise first. Then those "which are alive and remain will be caught up together with them in the clouds, to meet the Lord in the air."
Now, if the dead in Christ will rise first, that indicates a resurrection. There are two resurrections mentioned in the Bible. Rev. 20:4-5 mentions a resurrection of souls which will reign with Christ for a thousand years. It is explicitly mentioned that there are other souls which are dead but do not participate in the first resurrection. "Blessed and holy is he that hath part in the first resurrection:..." (20:6)
Then there is a final resurrection associated with the Great White Throne judgment. Rev. 21:11-15.
Since I Thessalonians is talking about Jesus' Second Coming, and includes a resurrection event we like to call The Rapture, this Rapture can only logically be associated with the first resurrection.
Looking at Rev. 19:11-16, we see a description of Jesus coming down from heaven on a white horse, with the armies which were in heaven following him upon white horses. That this army wore fine linen, white and clean, indicates these are the saints. Compare Rev. 20:8 with verse 14. There are also other verses in the Bible which indicate he is followed by the saints (Zech. 14:1-9, esp. vs. 5) as well as verses which indicate angels are coming with Him. (II Thess 1:7)
So here's my final take on it. The Rapture, which I like to call The Ingathering, is when the saints who are in heaven (dead) are reunited with their bodies (the first resurrection) while returning Jesus as part of an army of angels and saints on white horses. So exciting! As Jesus descends, saints who are not in heaven (still alive on earth) are caught up into the air to join this army.
The earthly army which was gathering against God's people, will unite to face this heavenly army which is descending. (Rev. 20:19) The earthly army loses, Jesus establishes his kingdom,
Rev. 20:4 indicates the souls which were martyred (specifically beheaded) for Jesus live and reign with him for a thousand years. What is not clear is if believers who were not martyred in this way also remain on earth.
The Bible is not entirely clear on this. However, looking at the scriptural evidence, my conclusion is that participants in this Ingathering with a First Resurrection will remain on earth to help with the new kingdom. The possibility that resurrected and raptured saints will simply return to heaven, perhaps to continue work on the upcoming New Jerusalem, is not as strong. However, I included both possibilities on the Heaven Flowchart as I did not have enough Biblical evidence to feel 100% sure about either option.
Oh, and one more thing about your Life after Life. Make sure you follow the blue line on the flowchart. It is amuch more fascinating journey than the red one!