You can pass the plusarg value from the command line and catch that value inside your sequence in a variable, later you can use that variable inside a loop where you generate the transactions.
For example,
if($value$plusargs("WR=%d",wr)) begin
`uvm_info (get_type_name(),$sformatf ("wr = %0d", wr), UVM_DEBUG)
end else begin
wr = 50;
`uvm_info (get_type_name(),$sformatf ("wr = %0d", wr), UVM_DEBUG)
end
rd = 100 - wr;
`uvm_info (get_type_name(),$sformatf ("rd = %0d", rd), UVM_DEBUG)
randcase
wr : begin
`uvm_do_on_with(wseq, seqr,
{
addr inside {[1:10]};
data == 100;
})
rd : begin
`uvm_do_on_with(rseq, seqr,
{
addr inside {[1:10]};
})
endcase