  We consider a scenario consisting of a set of heterogeneous mobile agents
located at a depot, and a set of tasks dispersed over a geographic area. The
agents are partitioned into different types. The tasks are partitioned into
specialized tasks that can only be done by agents of a certain type, and
generic tasks that can be done by any agent. The distances between each pair of
tasks are specified, and satisfy the triangle inequality. Given this scenario,
we address the problem of allocating these tasks among the available agents
(subject to type compatibility constraints) while minimizing the maximum cost
to tour the allocation by any agent and return to the depot. This problem is
NP-hard, and we give a three phase algorithm to solve this problem that
provides 5-factor approximation, regardless of the total number of agents and
the number of agents of each type. We also show that in the special case where
there is only one agent of each type, the algorithm has an approximation factor
of 4.
