A balanced incomplete block design 
is called resolvable if there exists a partition 
of its set of blocks 
into parallel classes, each
of which in turn partitions the set 
. The partition 
is called a resolution.
Resolvable
See also
Block Design, Parallel ClassExplore with Wolfram|Alpha
References
Abel, R. J. R. and Furino, S. C. "Resolvable and Near Resolvable Designs." §I.6 in The CRC Handbook of Combinatorial Designs (Ed. C. J. Colbourn and J. H. Dinitz). Boca Raton, FL: CRC Press, pp. 4 and 87-94, 1996.Furino, S.; Miao, Y.; and Yin, J. Frames and Resolvable Designs: Uses, Constructions, ad Existence. Boca Raton, FL: CRC Press, 1996.Referenced on Wolfram|Alpha
ResolvableCite this as:
Weisstein, Eric W. "Resolvable." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/Resolvable.html