diff --git a/prepshot/_model/investment.py b/prepshot/_model/investment.py
index 3b6d068..b878639 100644
--- a/prepshot/_model/investment.py
+++ b/prepshot/_model/investment.py
@@ -73,10 +73,6 @@ def __init__(self, model : object) -> None:
             model.year, model.zone, model.tech,
             rule=self.new_tech_low_bound_rule
         )
-        model.tech_lifetime_cons = poi.make_tupledict(
-            model.year, model.zone, model.tech,
-            rule=self.tech_lifetime_rule
-        )
 
     def tech_up_bound_rule(
         self, y : int, z : str, te : str