Modified d-optimal sequential procedure in allocation problem

When an experimenter wishes to compare t treatments with M experimental units, one of the first problems he faces is how to allocate N experimental units into t treatments. When no pre treat merit information about the experimental units is available, "randomization" is the widely accepted guiding principle to deal with the allocation problem But pre treat merit information usually is available, although it is seldom fully used for allocation purposes. Recently, Harville considered the allocation problem under a covariance model. He suggested a D-optimal sequential procedure that may be used to construct nearly D-optimal allocations. However, Harville's sequential procedure requires constructing a D-optimal initial allocation at the first stages and that may be computationally unfeasible in some real situations, Such construction is not needed for a new sequential.