Periodized training? If that's what you mean, it's basically a series of peaks and valleys in terms of effort. During a week, you can have hard days and easy days. During a month, you can have progressively harder weeks and then one easier week to recover. During a season, you can peak for events at different times.
Also, FTP refers to a power measurement, and it seems you are training by heart rate. Apples and oranges (relatively speaking). Power is the work you do, and heart rate is how your body responds to it. You want to work relative to your Lactic Threshold heart Rate.
The Time Crunched Cyclist book by Carmichael is one that some people new to training plans have had some success with. Easy enough to understand, although it's not as flexible or as responsive as a real cycling coach. There are all sorts of canned training plans available on the interwebs. First, figure out what you want to improve or train for, and then choose a plan that addresses that goal. I think that just about anyone that has been just hammering away at the same intensity could make some sufficient gains with a canned structured training program.