Back in 1994, I took the National Environmental Balancing Bureau (NEBB) TAB test that is formatted by beginning with an eight-hour written test. If you pass that, then you take a four-hour field test. The field test was completed at the University of Lowell (now UMASS Lowell) and was overseen by a professor at the university.
Yes, you are supposed to create a TAB plan long before you go out and start taking readings. To quote the book's introduction, "Testing, adjusting, and balancing personnel no longer can be just instrument readers, they must understand fully how to perform their work. Furthermore, they must understand at least the fundamentals of how these systems function, and use this knowledge to determine what is malfunctioning and how to correct it."