diff --git a/app/services/loft_service.py b/app/services/loft_service.py
index 74edc20..0e0db85 100644
--- a/app/services/loft_service.py
+++ b/app/services/loft_service.py
@@ -62,24 +62,35 @@ class LoftService(Base):
       problem = LpProblem("ata-form-generate", LpMinimize)
 
       # constraints
-      problem += lpSum([used[i]*items[i]
-                    for i in items]) == self.solver_run.total_form_items
-      
+      problem += lpSum([items[item.id]
+                    for item in self.solver_run.items]) == self.solver_run.total_form_items, 'Total form items'
+
+      for constraint in self.solver_run.constraints:
+        con = dict(zip([item.id for item in self.solver_run.items], 
+                       [item.attribute_exists(constraint.reference_attribute.id, constraint.reference_attribute.value)
+                       for item in self.solver_run.items]))
+        problem += lpSum([con[item.id]
+                         * items[item.id]
+                         for item in self.solver_run.items]) >= round(self.solver_run.total_form_items * (constraint.minimum / 100)), f'{constraint.reference_attribute.id} - {constraint.reference_attribute.value} - min'
+        problem += lpSum([con[item.id]
+                         * items[item.id]
+                         for item in self.solver_run.items]) <= round(self.solver_run.total_form_items * (constraint.maximum / 100)), f'{constraint.reference_attribute.id} - {constraint.reference_attribute.value} - max'
+
       # multi-objective functions and constraints
       for target in self.solver_run.objective_function.tif_targets:
           tif = lpSum([item.iif(self.solver_run, target.theta)*items[item.id]
                       for item in self.solver_run.items])
           problem += lpSum([item.iif(self.solver_run, target.theta)*items[item.id]
-                          for item in self.solver_run.items]) <= target.value
+                         for item in self.solver_run.items]) <= target.value, f'min tif theta ({target.theta}) target value {target.value}'
           problem_objection_functions.append(tif)
 
       for target in self.solver_run.objective_function.tcc_targets:
           tcc = lpSum([item.irf(self.solver_run, target.theta)*items[item.id]
                       for item in self.solver_run.items])
           problem += lpSum([item.irf(self.solver_run, target.theta)*items[item.id]
-                          for item in self.solver_run.items]) <= target.value
+                         for item in self.solver_run.items]) <= target.value, f'min tcc theta ({target.theta}) target value {target.value}'
           problem_objection_functions.append(tcc)
-      
+
       # solve problem
       problem.sequentialSolve(problem_objection_functions)