diff --git a/generate-n b/generate-n
index 19dbc11..df1b3d4 100755
--- a/generate-n
+++ b/generate-n
@@ -6,7 +6,7 @@ then
 fi
 if [ $# == 0 ] || [ $1 == "-help" ]
 then
-  echo "Generator options: ./generate-n <number of versions> ?<init number of products>"
+  echo "Generator options: ./generate-n <number of versions> ?<init number of products> ?<products step> ?<products variability>"
 fi
 # check that $1 is a integer
 if ! [[ $1 =~ ^[0-9]+$ ]]
@@ -16,13 +16,16 @@ then
 fi
 
 number_of_versions=$1
-products_number=${2:-1}
+products_number=${2:-100}
+products_step=${3:-1000}
+products_variability=${4:-1}
 echo "Generating $number_of_versions versions"
+echo "Setting products to $products_number, products step to $products_step and variability to $products_variability"
 
 # loop through the number of versions and call ./generate
 for i in $(seq 1 $number_of_versions)
 do
   echo "Generating version $i"
-  echo "Generating $((products_number + i)) products"
-  ./generate -s ttl -pc $((products_number + i)) -tc $((i)) -ppt $((i)) -fn "dataset-$i"
+  echo "Generating $((products_number + i * products_step)) products"
+  ./generate -s ttl -pc $((products_number + i * products_step)) -tc $((i * products_step)) -ppt $((i * products_variability)) -fn "dataset-$i"
 done