diff --git a/modules/purchase_trade/purchase.py b/modules/purchase_trade/purchase.py
index 57c668b..6a315a9 100755
--- a/modules/purchase_trade/purchase.py
+++ b/modules/purchase_trade/purchase.py
@@ -773,6 +773,13 @@ class PayableRule(ModelSQL, ModelView):
     deduction_value = fields.Numeric("Deduction Value")
     deduction_unit = fields.Many2One('assay.unit',"Unit")
 
+    payable_method = fields.Selection([
+        ('percent', 'Fixed %'),
+        ('grade_minus', 'Grade minus deduction'),
+        ('min_of_both', 'Min(% of grade, grade - deduction)'),
+    ], "Method")
+    min_payable = fields.Numeric("Floor (min payable)")  # ex: le "min -1" du Cu
+
 class PenaltyRule(ModelSQL, ModelView):
     "Penalty Rule"
     __name__ = 'penalty.rule'
diff --git a/modules/purchase_trade/purchase.xml b/modules/purchase_trade/purchase.xml
index 2576cbd..120f673 100755
--- a/modules/purchase_trade/purchase.xml
+++ b/modules/purchase_trade/purchase.xml
@@ -205,6 +205,12 @@ this repository contains the full copyright notices and license terms. -->
             <field name="name">concentrate_form</field>
         </record>
 
+        <record model="ir.ui.view" id="payable_rule_view_form">
+            <field name="model">payable.rule</field>
+            <field name="type">form</field>
+            <field name="name">payable_rule_form</field>
+        </record>
+
         <menuitem
             name="Pnl Report"
 	        parent="purchase_trade.menu_global_reporting"
diff --git a/modules/purchase_trade/view/payable_rule_form.xml b/modules/purchase_trade/view/payable_rule_form.xml
new file mode 100644
index 0000000..e36858d
--- /dev/null
+++ b/modules/purchase_trade/view/payable_rule_form.xml
@@ -0,0 +1,19 @@
+<form>
+    <label name="name"/>
+    <field name="name"/>
+    <label name="element"/>
+    <field name="element"/>
+    <newline/>
+    <label name="payable_method"/>
+    <field name="payable_method"/>
+    <label name="payable_percent"/>
+    <field name="payable_percent"/>
+    <newline/>
+    <label name="deduction_value"/>
+    <field name="deduction_value"/>
+    <label name="deduction_unit"/>
+    <field name="deduction_unit"/>
+    <newline/>
+    <label name="min_payable"/>
+    <field name="min_payable"/>
+</form>
\ No newline at end of file