How does your school system handle computer maintenance?

One client, a school system, has a quantity or spare units equivilent to ten percent of their total number in each location. Once a week I stop at each location I'm assigned to, twelve in total, and pickup any failed units and return repaired units. We are also responsible for the networks but they seldom give us much trouble. We have three other techs who handle a like number of locations and we return our bad units to a single location where in-house techs do the repairs and if neccesary reload the OS.