Ok. I think I now understand. The reason they must be parallel is because these teachers are 'self-contained'. It is the only teacher that teaches all of those subjects. For example:
Grade 1 Teacher teaches: Math, Science, English, Religion, Social Studies. This teacher needs a planning bell.
When they aren't teaching the subjects above and are in their planning bell, the first grade students have the option of being in either music, PE, computers, or art (what we call specials).
I am allowing the software to choose when the Planning Bell can occur as well as the specials for scheduling purposes.
Grade 1 Teacher teaches: Math, Science, English, Religion, Social Studies. This teacher needs a planning bell.
When they aren't teaching the subjects above and are in their planning bell, the first grade students have the option of being in either music, PE, computers, or art (what we call specials).
I am allowing the software to choose when the Planning Bell can occur as well as the specials for scheduling purposes.