Group Divisible Designs with Equal-Sized Holes

In this paper we consider group divisible designs with equal-sized holes \((HGDD)\) which is a generalization of modified group divisible designs \([1]\) and \(HMOLS\). We prove that the obvious necessary conditions for the existence of the \(HGDD\) is sufficient when the block size is three, which generalizes the result of Assaf[1].