My understanding is that there are three quarters each year. Each quarter, you will do two modules. So six modules will be completed in two years time. After that course work, you will have 6 months to complete your thesis/ dissertation. If you can complete your paper in 5 hours after enrolling in this or that module, then practically speaking, your work for that module is done. Though that is generally not how a student would proceed. Instead, he/ she will do the required reading over a couple months time, and then spend the remainder of the time crafting his/ her paper. You can take longer than 6 months to do your dissertation if you like, but you carefully plan it out with your advisor, tailoring the content and timing with them according to your needs. I found my writing tutors and my advisor at Birmingham to be VERY sensitive to my abilities, my needs, so it all went smoothly.