diff --git a/sentier_data_tools/__init__.py b/sentier_data_tools/__init__.py
index c1e2247..f43eb7a 100644
--- a/sentier_data_tools/__init__.py
+++ b/sentier_data_tools/__init__.py
@@ -3,11 +3,14 @@
 __all__ = (
     "__version__",
     "Datapackage",
-    "DatapackageWriter" "ProductIRI",
-    "Record",
-    "UnitIRI",
+    "DatapackageWriter",
     "example_data_dir",
+    "GeonamesIRI",
+    "ModelTermIRI",
+    "Record",
+    "ProductIRI",
     "reset_local_database",
+    "UnitIRI",
 )
 
 __version__ = "0.1.3"
@@ -15,7 +18,7 @@
 from pathlib import Path
 
 from sentier_data_tools.datapackage import DatapackageWriter
-from sentier_data_tools.iri import ProductIRI, UnitIRI
+from sentier_data_tools.iri import ProductIRI, UnitIRI, ModelTermIRI, GeonamesIRI
 from sentier_data_tools.local_data_store import (
     Datapackage,
     Record,
diff --git a/sentier_data_tools/common.py b/sentier_data_tools/common.py
new file mode 100644
index 0000000..aae6158
--- /dev/null
+++ b/sentier_data_tools/common.py
@@ -0,0 +1,41 @@
+from typing import Optional
+from pydantic import BaseModel
+import pandas as pd
+from datetime import date
+
+from sentier_data_tools.iri import ProductIRI, GeonamesIRI
+
+
+class Demand(BaseModel):
+    product_iri: ProductIRI
+    properties: Optional[list]
+    amount: float
+    spatial_context: GeonamesIRI = GeonamesIRI("https://sws.geonames.org/6295630/")
+    begin_date: Optional[date] = None
+    end_date: Optional[date] = None
+
+
+class RunConfig(BaseModel):
+    num_samples: int = 1000
+
+
+class SentierModel:
+    def __init__(self, demand: Demand, run_config: RunConfig):
+        self.demand = demand
+        self.run_config = run_config
+        if self.run_config.begin_date is None:
+            self.run_config.begin_date = date(date.today().year - 5, 1, 1)
+        if self.run_config.end_date is None:
+            self.run_config.end_date = date(date.today().year + 5, 1, 1)
+
+    def get_model_data(self) -> list[pd.DataFrame]:
+        pass
+
+    def prepare(self) -> None:
+        self.get_model_data()
+        self.data_validity_checks()
+        self.resample()
+
+    def run(self) -> list[Demand]:
+        pass
+
diff --git a/sentier_data_tools/example_model.py b/sentier_data_tools/example_model.py
new file mode 100644
index 0000000..e69de29
diff --git a/sentier_data_tools/iri.py b/sentier_data_tools/iri.py
index 14c478b..14c1f5b 100644
--- a/sentier_data_tools/iri.py
+++ b/sentier_data_tools/iri.py
@@ -79,4 +79,12 @@ class ProductIRI(VocabIRI):
 
 
 class UnitIRI(VocabIRI):
-    graph_url = "https://vocab.sentier.dev/qudt/"
+    graph_url = "https://vocab.sentier.dev/units/"
+
+
+class ModelTermIRI(VocabIRI):
+    graph_url = "https://vocab.sentier.dev/model-terms/"
+
+
+class GeonamesIRI(URIRef):
+    pass
diff --git a/sentier_data_tools/local_data_store.py b/sentier_data_tools/local_data_store.py
index 21a52e7..05e390d 100644
--- a/sentier_data_tools/local_data_store.py
+++ b/sentier_data_tools/local_data_store.py
@@ -69,11 +69,15 @@ class Record(Model):
     class Meta:
         database = db
 
+    @property
+    def dataframe(self):
+        return self.data.to_pandas()
+
 
 # Function to query records by a column name
 def query_records_by_column(column_value):
     """Returns a list of records where the specified column is present."""
     query = Record.select().where(
-        fn.JSON_CONTAINS(Record.columns, f'["{column_value}"]')
+        fn.JSON_CONTAINS(Record.columns, column_value)
     )
     return list(query)
diff --git a/tests/integration/test_product_iri.py b/tests/integration/test_product_iri.py
index e69de29..4960444 100644
--- a/tests/integration/test_product_iri.py
+++ b/tests/integration/test_product_iri.py
@@ -0,0 +1,2 @@
+from sentier_data_tools import ProductIRI
+