diff --git a/ogstools/studies/efficiency/__init__.py b/ogstools/studies/efficiency/__init__.py
new file mode 100644
index 0000000000000000000000000000000000000000..03fd83ec0f8247e9f070c48add4dfa3f07bc1f7e
--- /dev/null
+++ b/ogstools/studies/efficiency/__init__.py
@@ -0,0 +1,26 @@
+# Author: Tobias Meisel (Helmholtz Centre for Environmental Research GmbH - UFZ)
+"""functions to generate a convergence study."""
+
+from .common_ogs_analyses import (
+    analysis_convergence_coupling_iteration,
+    analysis_convergence_newton_iteration,
+    analysis_simulation,
+    analysis_simulation_termination,
+    analysis_time_step,
+    fill_ogs_context,
+    time_step_vs_iterations,
+)
+from .log_parser import parse_file
+from .ogs_regexes import ogs_regexes
+
+__all__ = [
+    "parse_file",
+    "analysis_convergence_coupling_iteration",
+    "analysis_simulation",
+    "analysis_convergence_newton_iteration",
+    "analysis_simulation_termination",
+    "analysis_time_step",
+    "fill_ogs_context",
+    "time_step_vs_iterations",
+    "ogs_regexes",
+]