To expand a bit on what I was saying about the rep maxes...
At the end of each cycle, I recommend at least a week, preferably two (or more if you can keep progressing) after you hit your tested 5 rep max. You should continue with the 5s and keep adding weight each session until you eventually hit failure on each lift - you do not have to hit failure on the same day for each lift, I will often find a new max on Monday for one or two lifts, a new max on Weds for a couple more then the rest on Friday, as an example. Write these numbers down and use those to plan out your next cycle. It is not necessary to find your 15 and 10 rep maxes again for each cycle. Just base the cycle off your new 5 rep maxes and either use a rep max calculator based on your new 5 RMs to estimate your new 10 and 15 RMs, or else figure out the percentage of increase between your old 5 RM and new 5 RM, and use that percentage to figure out what to add on to get your new 10 and 15 RMs.
This will save you a lot of time versus testing for new maxes at the end of each cycle.
Also keep in mind that since you are going to be taking an SD at the end of your cycle, hitting failure is ok during the last couple weeks. Also, it is acceptable (even encouraged depending on circumstances) to continue using your new 5 RMs once you've found them for another week or two. I like to keep pushing for more strength gains during this period - which also means that you might even increase your new 5 RMs even more prior to your next cycle.