This is another somewhat parameterized version.    %let center=5; %let block=6; %let ratio = 1 1 2 2 3; %let treat=%sysfunc(countw(%superq(ratio))); %let subject=%eval(&center*&block*&treat); %put _global_; proc format; value trt 1='Active Low Dose' 2='Active High Dose' 3='Placebo'; quit; proc plan; factors center=&center ordered block=&block ordered treat=&treat random subject=1 of &subject perm / noprint; output out=plan treat nvals=(&ratio) random; run; quit; data plan; retain SYSRANDOM &SYSRANDOM SYSRANEND &SYSRANEND; set plan; length usubjid $16; usubjid = catx('-','XYZ-01',vvalue(center),vvalue(subject)); format subject center z3.; run; proc print; run; ... View more