Let us consider a module M having m elements. To each element of the module, there corresponds n distinct classes, where m >= 5 and n >= 2. With these v = mn treatments following are parameters of the three-associate class PBIB design:
v = mn,  b = mn,  r = (m+n-1),  k = (m+n-1)
lambda 1 = m,  lambda 2 = 2,  lambda 3 = n