PROC SURVEYSELECT METHOD=PPS Error

Hello All,

I am working on a project where we need to sample some items in a
warehouse with the higher dollar items having a higher chance of being
picked. When I ran the data through PROC SURVEYSELECT METHOD=PPS I
get the following error "the relatize size of each sampling unit must
not exceed 1/sampsize.


If I redued the sample size to 7 this error goes away, unfortunately I
need a sample size of 37.


After soon searching, i found some posts on SAS-L and sas.support to
find the maximum sample size to use(http://support.sas.com/kb/
23/759.html) that stop this problem from happening or to use the
MINSIZE, MAXSIZE, CERTSIZE options (via a few SAS-L post from David
Cassel). By toying with the CERTSIZE I got it to work, but the logic
behind the MINSIZE and MAXSIZE escapes me. I just don't want the PROC
to work by trial and error, I want to UNDERSTAND why it works and
that's is where I am missing something. Hopefully, the SAS-Lers can
help.

I created a test data set that is fairly representitive of what my
inventory data looks like. For some reason I can't paste my code in
here so I hope I make no typos


data one;
do id=1 to 183;
lag_value=value;
if id le 1 then value=id;
else value=lag_value*1.05;
lag_value=lag(value);
output;
end;

run;


* this outputs as error;

proc surveyselect data=one method=pps seed=6845 n=37 out=sample_one;
size value;
run;


By using n=20 the error goes away;


Any guidance on using MINSIZE or MAXSIZE would be appreciated.


-Darryl