diff --git a/Netzqualität_Zuverlässigkeit.py b/Netzqualität_Zuverlässigkeit.py
new file mode 100644
index 0000000..60442b6
--- /dev/null
+++ b/Netzqualität_Zuverlässigkeit.py
@@ -0,0 +1,109 @@
+from dataclasses import dataclass
+from typing import Sequence, List, Dict
+import sympy as sp
+
+
+@dataclass
+class Zuverlaessigkeit:
+
+    def redundanzanalyse(self, r_vec: Sequence[float]) -> Dict[str, object]:
+        r_s = [sp.sympify(r) for r in r_vec]
+        EVi = [float(r * 100) for r in r_s]
+        klassen = [self.klassifiziere_ri(float(r)) for r in r_s]
+
+        return {
+            "r_i": [float(r) for r in r_s],
+            "EVi": EVi,
+            "klassen": klassen,
+            "r_sum": float(sum(r_s)),
+            "min_r": float(min(r_s)),
+            "max_r": float(max(r_s)),
+        }
+
+
+
+    def klassifiziere_ri(self, ri: float) -> str:
+        if ri < 0.01:
+            return "nicht kontrollierbar"
+        elif ri < 0.10:
+            return "schlecht kontrollierbar"
+        elif ri < 0.30:
+            return "ausreichend kontrollierbar"
+        elif ri < 0.70:
+            return "gut kontrollierbar"
+        else:
+            return "nahezu vollständig redundant"
+
+
+
+    def globaltest(self, sigma0_hat: float, sigma0_apriori: float, F_krit: float):
+        s_hat = sp.sympify(sigma0_hat)
+        s0 = sp.sympify(sigma0_apriori)
+        Fk = sp.sympify(F_krit)
+
+        T_G = (s_hat**2) / (s0**2)
+        H0 = bool(T_G <= Fk)
+
+        return {
+            "T_G": float(T_G),
+            "F_krit": float(Fk),
+            "H0_angenommen": H0,
+        }
+
+
+
+    def data_snooping(
+        self,
+        v: Sequence[float],
+        Qv_diag: Sequence[float],
+        r_vec: Sequence[float],
+        sigma0_hat: float,
+        k: float,
+    ) -> List[Dict[str, float | bool]]:
+
+        v_s = [sp.sympify(x) for x in v]
+        Qv_s = [sp.sympify(q) for q in Qv_diag]
+        r_s = [sp.sympify(r) for r in r_vec]
+        s0 = sp.sympify(sigma0_hat)
+        k_s = sp.sympify(k)
+
+        results = []
+
+        for vi, Qvi, ri in zip(v_s, Qv_s, r_s):
+
+            s_vi = s0 * sp.sqrt(Qvi)
+            NV_i = sp.Abs(vi) / s_vi
+
+            if ri == 0:
+                GRZW_i = sp.oo
+            else:
+                GRZW_i = (s_vi / ri) * k_s
+
+            auff = bool(NV_i > k_s)
+
+            results.append({
+                "v_i": float(vi),
+                "Qv_i": float(Qvi),
+                "r_i": float(ri),
+                "s_vi": float(s_vi),
+                "NV_i": float(NV_i),
+                "GRZW_i": float(GRZW_i if GRZW_i != sp.oo else float("inf")),
+                "auffällig": auff,
+            })
+
+        return results
+
+
+
+    def aeussere_zuverlaessigkeit_EF(self, r_vec: Sequence[float], delta0: float):
+        delta = sp.sympify(delta0)
+        EF_list = []
+        for ri in r_vec:
+            ri_s = sp.sympify(ri)
+            if ri_s == 0:
+                EF = sp.oo
+            else:
+                EF = sp.sqrt((1 - ri_s) / ri_s) * delta
+            EF_list.append(float(EF if EF != sp.oo else float("inf")))
+
+        return EF_list
\ No newline at end of file
diff --git a/Parameterschaetzung.py b/Parameterschaetzung.py
index 078c600..28f4d1b 100644
--- a/Parameterschaetzung.py
+++ b/Parameterschaetzung.py
@@ -23,7 +23,7 @@ def iterative_ausgleichung(
 
         v = l - A * dx                                  #Residuenvektor v
 
-        Q_vv = modell.berechne_Qvv(A, Q_ll, Q_xx)       #Kofaktormatrix der Verbesserungen Qvv
+        Q_vv = modell.berechne_Qvv(A, P, Q_xx)       #Kofaktormatrix der Verbesserungen Qvv
         R = modell.berechne_R(Q_vv, P)                  #Redundanzmatrix R
         r = modell.berechne_r(R)                        #Redundanzanteile als Vektor r
 
@@ -44,10 +44,21 @@ def iterative_ausgleichung(
             "sigma0_groups": dict(modell.sigma0_groups),
         })
 
-        if all(abs(val - 1.0) < tol for val in sigma_hat.values()):         #Abbruchkriterium
-            print(f"Konvergenz nach {it + 1} Iterationen erreicht.")
-            break
+        # --- Abbruchkriterium ---
+        if sigma_hat:
+            max_rel_change = 0.0
+            for g, new_val in sigma_hat.items():
+                old_val = modell.sigma0_groups.get(g, 1.0)
+                if old_val != 0:
+                    rel = abs(new_val - old_val) / abs(old_val)
+                    max_rel_change = max(max_rel_change, rel)
 
+            if max_rel_change < tol:
+                print(f"Konvergenz nach {it + 1} Iterationen erreicht (max. rel. Änderung = {max_rel_change:.2e}).")
+                modell.update_sigma0_von_vks(sigma_hat)
+                break
+
+        # Varianzfaktoren für nächste Iteration übernehmen
         modell.update_sigma0_von_vks(sigma_hat)
 
     return {
diff --git a/Stochastisches_Modell.py b/Stochastisches_Modell.py
index 144d497..8b127d8 100644
--- a/Stochastisches_Modell.py
+++ b/Stochastisches_Modell.py
@@ -42,8 +42,8 @@ class StochastischesModell:
         return Q_ll, P
 
 
-    def berechne_Qvv(self, A: sp.Matrix, Q_ll: sp.Matrix, Q_xx: sp.Matrix) -> sp.Matrix:
-        Q_vv = Q_ll - A * Q_xx * A.T
+    def berechne_Qvv(self, A: sp.Matrix, P: sp.Matrix, Q_xx: sp.Matrix) -> sp.Matrix:
+        Q_vv = P.inv() - A * Q_xx * A.T
         return Q_vv                                 #Kofaktormatrix der Beobachtungsresiduen