Where possible it is usually advantageous to construct resolvable designs. With such designs a term for replicates can be included in the analysis to remove extraneous variation in a very efficient manner; we say that replicates and treatments are orthogonal to each other.
Neighbour balance and evenness of distribution
A common problem with classical randomized row-column designs is that replications of a treatment may be clustered together or appear as self-diagonals and some pairs of treatments may appear next to each other rather more often than others.
A spatial (NB&ED) block design or row-column design takes into account the separation of different treatments in blocks. CycDesigN can adapt block and row-column designs to achieve good neighbour balance and evenness of distribution.