diff --git a/.gitignore b/.gitignore
index 7a65ece..b103cd9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,8 @@
 .venv/
-output/
+output/*
 src/logwatcher/__pycache__/
 *.log
 
-__pycache__
\ No newline at end of file
+__pycache__
+docs/convention*
+docs/resultats.json
\ No newline at end of file
diff --git a/.vscode/launch.json b/.vscode/launch.json
index 46f4007..bfaa7b2 100644
--- a/.vscode/launch.json
+++ b/.vscode/launch.json
@@ -1,6 +1,7 @@
 {
     "version": "0.2.0",
     "configurations": [
+
         {
             "name": "Python Debugger: Current File",
             "type": "debugpy",
@@ -15,7 +16,31 @@
             "cwd": "${workspaceFolder}",
             "console": "integratedTerminal",
             "module": "logwatcher.app",
-            //"program": "${workspaceFolder}\\.venv\\Scripts\\logwatcher.exe"
+        },
+        {
+            "name": "Python Test: Current File",
+            "type": "debugpy",
+            "request": "launch",
+            "program": "pytest",
+            "args": [
+                "-p",
+                "vscode_pytest", 
+                "--rootdir=${workspaceFolder}",
+                "--capture=no",
+                "${file}"
+            ]
+        },
+        {
+            "name": "Python Test: All tests",
+            "type": "debugpy",
+            "request": "launch",
+            "program": "pytest",
+            "args": [
+                "-p",
+                "vscode_pytest", 
+                "--rootdir=${workspaceFolder}",
+                "--capture=no"
+            ]
         }
     ]
 }
\ No newline at end of file
diff --git a/pyproject.toml b/pyproject.toml
index 4577fac..0855b6d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,11 @@ version = "0.1.0"
 description = "Trier, classifier et extraire automatiquement les entrées pertinentes d'un fichier de logs applicatif."
 readme = "README.md"
 requires-python = ">=3.10"
-dependencies = [
+dependencies = []
+
+[dependency-groups]
+dev = [
+    "ruff>=0.16.0",
     "mypy>=2.3.0",
     "pytest>=9.1.1",
 ]
@@ -12,11 +16,6 @@ dependencies = [
 [project.scripts]
 logwatcher = "logwatcher.app:app"
 
-[project.optional-dependencies]
-dev = [
-    "ruff>=0.16.0",
-    "mypy>=2.3.0",
-]
 
 [build-system]
 requires = ["hatchling"]
diff --git a/src/logwatcher/__init__.py b/src/logwatcher/__init__.py
index 1898185..2ec9f74 100644
--- a/src/logwatcher/__init__.py
+++ b/src/logwatcher/__init__.py
@@ -1,3 +1,4 @@
+from logwatcher.config import *
 from logwatcher.logging import setup_logging
 
 logger = setup_logging() 
diff --git a/src/logwatcher/config.py b/src/logwatcher/config.py
index 694ce31..d3f1907 100644
--- a/src/logwatcher/config.py
+++ b/src/logwatcher/config.py
@@ -1,9 +1,40 @@
+import re
+from datetime import timedelta, timezone
 from pathlib import Path
 
+### GENERAL DATA
 # output path
 OUTPUT_PATH = Path("output")
 RESULT_PATH = OUTPUT_PATH / "results"
 LOGGING_PATH = OUTPUT_PATH / "logs"
 
-# fixture path
-FIXTURE_PATH = Path.cwd() / "fixtures"
\ No newline at end of file
+# test path
+TEST_PATH = Path("tests")
+FIXTURE_PATH = TEST_PATH / "fixtures"
+
+# date and time
+DATETIME_FORMAT = "%d/%m/%Y %H:%M:%S"
+FRENCH_TIMEZONE = timezone(offset=timedelta(hours=2))  # UTC+2 = CEST
+
+
+### LOG DATA
+### definition of log pattern
+SERVER_IP_PATTERN = r"([1-9]\d{1,2}\.)(0{1}|\d{1,3}\.){2}(0{1}|\d{1,3})"
+MDC_SERVER_NAME_PATTERN = r"MDC_\d+"
+DATE_TIME_PATTERN = r"((0[1-9])|([1-2][0-9])|(3[0-1]))/((0[1-9])|(1[0-2]))/\d{4} (([0-1][0-9])|(2[0-3])):[0-5][0-9]:[0-5][0-9]"
+STORE_NAME_PATTERN = r"[^\[]+"
+ERROR_MESSAGE_PATTERN = r".*"
+
+LOG_PATTERN = re.compile(
+    r"\\\\"
+    rf"(?P<server_ip>{SERVER_IP_PATTERN})"
+    r"\\[^\\]+\\"
+    rf"(?P<mdc_server_name>{MDC_SERVER_NAME_PATTERN})"
+    r"[\\\w ]+\.\w+ \["
+    rf"(?P<start_time>{DATE_TIME_PATTERN})"
+    r"\] DOSSIER EN COURS : "
+    rf"(?P<store_name>{STORE_NAME_PATTERN})"
+    rf" \[(?P<error_time>{DATE_TIME_PATTERN})\] "
+    rf"(?P<error_message>{ERROR_MESSAGE_PATTERN})",
+    re.VERBOSE
+)
\ No newline at end of file
diff --git a/src/logwatcher/models.py b/src/logwatcher/models.py
new file mode 100644
index 0000000..ada80bb
--- /dev/null
+++ b/src/logwatcher/models.py
@@ -0,0 +1,62 @@
+import re
+from dataclasses import dataclass
+from datetime import datetime
+
+from logwatcher import DATETIME_FORMAT, FRENCH_TIMEZONE
+from logwatcher.config import (
+    DATE_TIME_PATTERN,
+    ERROR_MESSAGE_PATTERN,
+    MDC_SERVER_NAME_PATTERN,
+    SERVER_IP_PATTERN,
+    STORE_NAME_PATTERN,
+)
+
+
+@dataclass()
+class LogEntry:
+    """
+        Represents a line in log file.
+    """
+    server_ip: str 
+    mdc_server_name: str
+    start_time: datetime
+    store_name: str
+    error_time: datetime
+    error_message: str
+    raw_line: str  # full initial log
+
+    def __str__(self):
+        return self.error_message
+    
+    def get_full_message(self):
+        return self.raw_line
+
+    def get_start_time(self):
+        return datetime.strftime(DATETIME_FORMAT, tz=FRENCH_TIMEZONE)
+
+    def __post_init__(self):
+        """
+            Each property must be validated by specific regex defined in config.py
+        """
+        if not re.search(SERVER_IP_PATTERN, self.server_ip):
+            raise ValueError(f"Server IP '{self.server_ip}' must be a valid IPV4.")
+
+        if not re.search(MDC_SERVER_NAME_PATTERN, self.mdc_server_name):
+            raise ValueError(f"MDC server name '{self.mdc_server_name}' must be in format {MDC_SERVER_NAME_PATTERN}.")
+
+        if not re.search(DATE_TIME_PATTERN, self.start_time.strftime(DATETIME_FORMAT)):
+            raise ValueError(f"Start time '{self.start_time}' must be in format {DATE_TIME_PATTERN}.")
+
+        if not re.search(STORE_NAME_PATTERN, self.store_name):
+            raise ValueError(f"Store name '{self.store_name}' must be a string with only alphanumeric characters, '-', '_', or ' '.")
+
+        if not re.search(DATE_TIME_PATTERN, self.error_time.strftime(DATETIME_FORMAT)):
+            raise ValueError(f"Error time '{self.error_time}' must be in format {DATE_TIME_PATTERN}.")
+
+        if not re.search(ERROR_MESSAGE_PATTERN, self.error_message):
+            raise ValueError("No error message found.")
+
+        ### LOGIC ERRORS ###
+        # error time cannot be earlier than start time
+        if self.start_time > self.error_time:
+            raise ValueError(f"Error in date-times : error_time '{self.error_time}' cannot be earlier than start_time '{self.start_time}")
diff --git a/fixtures/CR.txt b/tests/fixtures/CR.txt
similarity index 100%
rename from fixtures/CR.txt
rename to tests/fixtures/CR.txt
diff --git a/fixtures/CR_20260718150816.txt b/tests/fixtures/CR_20260718150816.txt
similarity index 100%
rename from fixtures/CR_20260718150816.txt
rename to tests/fixtures/CR_20260718150816.txt
diff --git a/fixtures/CR_20260727110008.txt b/tests/fixtures/CR_20260727110008.txt
similarity index 100%
rename from fixtures/CR_20260727110008.txt
rename to tests/fixtures/CR_20260727110008.txt
diff --git a/fixtures/CR_20260727110725.txt b/tests/fixtures/CR_20260727110725.txt
similarity index 100%
rename from fixtures/CR_20260727110725.txt
rename to tests/fixtures/CR_20260727110725.txt
diff --git a/fixtures/CR_20260727190008.txt b/tests/fixtures/CR_20260727190008.txt
similarity index 100%
rename from fixtures/CR_20260727190008.txt
rename to tests/fixtures/CR_20260727190008.txt
diff --git a/fixtures/CR_20260727190805.txt b/tests/fixtures/CR_20260727190805.txt
similarity index 100%
rename from fixtures/CR_20260727190805.txt
rename to tests/fixtures/CR_20260727190805.txt
diff --git a/fixtures/CR_20260728110838.txt b/tests/fixtures/CR_20260728110838.txt
similarity index 100%
rename from fixtures/CR_20260728110838.txt
rename to tests/fixtures/CR_20260728110838.txt
diff --git a/fixtures/CR_bl_auto_bestseller.txt b/tests/fixtures/CR_bl_auto_bestseller.txt
similarity index 100%
rename from fixtures/CR_bl_auto_bestseller.txt
rename to tests/fixtures/CR_bl_auto_bestseller.txt
diff --git a/fixtures/CR_rejet_taille.txt b/tests/fixtures/CR_rejet_taille.txt
similarity index 100%
rename from fixtures/CR_rejet_taille.txt
rename to tests/fixtures/CR_rejet_taille.txt
diff --git a/fixtures/CR_tva.txt b/tests/fixtures/CR_tva.txt
similarity index 100%
rename from fixtures/CR_tva.txt
rename to tests/fixtures/CR_tva.txt
diff --git a/tests/test_models.py b/tests/test_models.py
new file mode 100644
index 0000000..a120aa4
--- /dev/null
+++ b/tests/test_models.py
@@ -0,0 +1,53 @@
+from datetime import datetime
+
+import pytest
+
+from logwatcher import DATETIME_FORMAT, FRENCH_TIMEZONE
+from logwatcher.models import LogEntry
+
+
+def test_valid_log_entry():
+    LogEntry(
+        server_ip="192.168.13.27",
+        mdc_server_name="MDC_720",
+        start_time=datetime.strptime("18/07/2026 11:34:41", DATETIME_FORMAT).astimezone(FRENCH_TIMEZONE),
+        store_name="PECCOUD",
+        error_time=datetime.strptime("18/07/2026 11:35:58", DATETIME_FORMAT).astimezone(FRENCH_TIMEZONE),
+        error_message="Erreur FTP SDUpdatePrixISF : Requested action not taken",
+        raw_line="\\\\192.168.13.27\\e\\MDC_720\\Logs\\26\\07\\18\\20260718113428.txt [18/07/2026 11:34:41] DOSSIER EN COURS : PECCOUD [18/07/2026 11:35:58] Erreur FTP SDUpdatePrixISF : Requested action not taken"
+    )
+
+def test_log_entry_invalid_dates():
+    with pytest.raises(ValueError, match="Error in date-times"):
+        LogEntry(
+            server_ip="192.168.13.27",
+            mdc_server_name="MDC_720",
+            start_time=datetime.strptime("18/07/2026 11:35:58", DATETIME_FORMAT).astimezone(FRENCH_TIMEZONE),
+            store_name="PECCOUD",
+            error_time=datetime.strptime("18/07/2026 11:34:41", DATETIME_FORMAT).astimezone(FRENCH_TIMEZONE),
+            error_message="Erreur FTP SDUpdatePrixISF : Requested action not taken",
+            raw_line="\\\\192.168.13.27\\e\\MDC_720\\Logs\\26\\07\\18\\20260718113428.txt [18/07/2026 11:34:41] DOSSIER EN COURS : PECCOUD [18/07/2026 11:35:58] Erreur FTP SDUpdatePrixISF : Requested action not taken"
+        )
+
+def test_equals_models():
+    log_entry_1 = LogEntry(
+        server_ip="192.168.13.27",
+        mdc_server_name="MDC_720",
+        start_time=datetime.strptime("18/07/2026 11:34:41", DATETIME_FORMAT).astimezone(FRENCH_TIMEZONE),
+        store_name="PECCOUD",
+        error_time=datetime.strptime("18/07/2026 11:35:58", DATETIME_FORMAT).astimezone(FRENCH_TIMEZONE),
+        error_message="Erreur FTP SDUpdatePrixISF : Requested action not taken",
+        raw_line="\\\\192.168.13.27\\e\\MDC_720\\Logs\\26\\07\\18\\20260718113428.txt [18/07/2026 11:34:41] DOSSIER EN COURS : PECCOUD [18/07/2026 11:35:58] Erreur FTP SDUpdatePrixISF : Requested action not taken"
+    )
+
+    log_entry_2 = LogEntry(
+        server_ip="192.168.13.27",
+        mdc_server_name="MDC_720",
+        start_time=datetime.strptime("18/07/2026 11:34:41", DATETIME_FORMAT).astimezone(FRENCH_TIMEZONE),
+        store_name="PECCOUD",
+        error_time=datetime.strptime("18/07/2026 11:35:58", DATETIME_FORMAT).astimezone(FRENCH_TIMEZONE),
+        error_message="Erreur FTP SDUpdatePrixISF : Requested action not taken",
+        raw_line="\\\\192.168.13.27\\e\\MDC_720\\Logs\\26\\07\\18\\20260718113428.txt [18/07/2026 11:34:41] DOSSIER EN COURS : PECCOUD [18/07/2026 11:35:58] Erreur FTP SDUpdatePrixISF : Requested action not taken"
+    )
+
+    assert log_entry_1 == log_entry_2
diff --git a/uv.lock b/uv.lock
index 37860b8..2713a5e 100644
--- a/uv.lock
+++ b/uv.lock
@@ -168,25 +168,22 @@ wheels = [
 name = "logwatcher"
 version = "0.1.0"
 source = { editable = "." }
-dependencies = [
-    { name = "mypy" },
-    { name = "pytest" },
-]
 
-[package.optional-dependencies]
+[package.dev-dependencies]
 dev = [
     { name = "mypy" },
+    { name = "pytest" },
     { name = "ruff" },
 ]
 
 [package.metadata]
-requires-dist = [
+
+[package.metadata.requires-dev]
+dev = [
     { name = "mypy", specifier = ">=2.3.0" },
-    { name = "mypy", marker = "extra == 'dev'", specifier = ">=2.3.0" },
     { name = "pytest", specifier = ">=9.1.1" },
-    { name = "ruff", marker = "extra == 'dev'", specifier = ">=0.16.0" },
+    { name = "ruff", specifier = ">=0.16.0" },
 ]
-provides-extras = ["dev"]
 
 [[package]]
 name = "mypy"