2014/Ch4/Drill4/pg195

[Guadalupe]

The eight librarians, does it matter if the afternoon shift is stacked above the morning shift?
(I stacked morning above afternoon).

Also, why is F>G? not
F
^
G

"Librarian F works an earlier shift than librarian G". (195)

Thanks for any additional insight.

[Nikki Siclunov]

Hi Guadalupe,

To answer your first question - no, it doesn't matter whether you put the afternoon shift above or below the morning shift.

If F works an earlier shift than G, the best way to represent the rule is horizontally, because we have a horizontal setup where the librarians are temporally ordered left to right. You are correct in that there is also a vertical order (morning/afternoon), so you may want to notate that in your setup. However, the vertical diagram you propose would be confusing, because - visually, at least, it suggests a vertical FG block. Obviously, F need not work in the morning, and G need not work in the afternoon (a block of this type is only necessary if we find that F must work in the morning of the last day, or else that G must work in the afternoon of the first day).

Hope this helps! Let me know.