diff --git a/WorkflowEngine.php b/WorkflowEngine.php
index 01467be..3a541f9 100644
--- a/WorkflowEngine.php
+++ b/WorkflowEngine.php
@@ -57,7 +57,7 @@ class WorkflowEngine {
         $people = $stmt_people->fetchAll(PDO::FETCH_ASSOC);
 
         // 4. Fetch all process definitions with their JSON
-        $stmt_defs = $this->pdo->prepare("SELECT id, name, definition_json, is_active FROM process_definitions WHERE is_active = 1 ORDER BY sort_order, name");
+        $stmt_defs = $this->pdo->prepare("SELECT id, code, name, definition_json, is_active FROM process_definitions WHERE is_active = 1 AND is_latest = 1 ORDER BY sort_order, name");
         $stmt_defs->execute();
         $process_definitions_raw = $stmt_defs->fetchAll(PDO::FETCH_ASSOC);
         
@@ -66,6 +66,7 @@ class WorkflowEngine {
         foreach ($process_definitions_raw as $def) {
             $definitions[$def['id']] = [
                 'id' => $def['id'],
+                'code' => $def['code'],
                 'name' => $def['name'],
                 'is_active' => $def['is_active']
             ];
@@ -122,7 +123,16 @@ class WorkflowEngine {
                     $enriched_instance['computed_next_step'] = $instance['suggested_next_step'];
                 }
                 
-                $instances[$instance['person_id']][$def_id] = $enriched_instance;
+                
+// Use process_code to map to the latest active column
+                $code = $instance['process_code'] ?? null;
+                if ($code && isset($codeToIdMap[$code])) {
+                    $latestDefId = $codeToIdMap[$code];
+                    // Only keep the most recently active instance per code (since ordered by last_activity_at DESC)
+                    if (!isset($instances[$instance['person_id']][$latestDefId])) {
+                        $instances[$instance['person_id']][$latestDefId] = $enriched_instance;
+                    }
+                }
             }
         }
 
@@ -513,6 +523,49 @@ class WorkflowEngine {
         $stmt->execute([$instanceId, $eventType, $message, $nodeId, json_encode($payload), $userId]);
     }
 
+        public function createNewInstance(int $personId, int $processDefinitionId, int $userId, array $context = []): array {
+        if (!is_int($processDefinitionId) || $processDefinitionId <= 0) {
+            throw new InvalidArgumentException("processDefinitionId must be a positive integer.");
+        }
+        if (!is_int($personId) || $personId <= 0) {
+            throw new InvalidArgumentException("personId must be a positive integer.");
+        }
+
+        $stmt_def = $this->pdo->prepare("SELECT definition_json, code, is_active FROM process_definitions WHERE id = ?");
+        $stmt_def->execute([$processDefinitionId]);
+        $definition = $stmt_def->fetch(PDO::FETCH_ASSOC);
+
+        if (!$definition) {
+            throw new WorkflowNotFoundException("Process definition #$processDefinitionId not found.");
+        }
+
+        if (empty($definition['is_active'])) {
+            throw new WorkflowNotAllowedException("Process is not active and cannot be started.");
+        }
+
+        $eligibility = $this->checkEligibility($personId, $processDefinitionId, $context);
+        if (!$eligibility['is_eligible']) {
+            throw new WorkflowEligibilityException("Person is not eligible to start this process.", $eligibility['reasons']);
+        }
+
+        $definition_json = !empty($definition['definition_json']) ? json_decode($definition['definition_json'], true) : [];
+        $start_node = $definition_json['start_node_id'] ?? 'start';
+        $initial_data_map = $definition_json['initial_data'] ?? [];
+        $data_json = !empty($initial_data_map) ? json_encode($initial_data_map) : null;
+
+        $stmt = $this->pdo->prepare(
+            "INSERT INTO process_instances (person_id, process_definition_id, current_node_id, current_status, data_json, last_activity_at) VALUES (?, ?, ?, 'in_progress', ?, NOW())"
+        );
+        $stmt->execute([$personId, $processDefinitionId, $start_node, $data_json]);
+        $newInstanceId = $this->pdo->lastInsertId();
+
+        $this->logEvent($newInstanceId, 'process_started', 'Process started', $start_node, ['context' => $context], $userId);
+
+        $stmt = $this->pdo->prepare("SELECT * FROM process_instances WHERE id = ?");
+        $stmt->execute([$newInstanceId]);
+        return $stmt->fetch(PDO::FETCH_ASSOC);
+    }
+
     public function getOrCreateInstanceByDefId(int $personId, int $processDefinitionId, int $userId, array $context = []): ?array {
         if (!is_int($processDefinitionId) || $processDefinitionId <= 0) {
             throw new InvalidArgumentException("processDefinitionId must be a positive integer.");
@@ -521,9 +574,7 @@ class WorkflowEngine {
             throw new InvalidArgumentException("personId must be a positive integer.");
         }
 
-        $stmt = $this->pdo->prepare("SELECT * FROM process_instances WHERE `person_id` = ? AND `process_definition_id` = ?");
-        $stmt->execute([$personId, $processDefinitionId]);
-        $instance = $stmt->fetch(PDO::FETCH_ASSOC);
+        $instance = $this->getInstanceByDefId($personId, $processDefinitionId);
 
         if (!$instance) {
             $stmt_def = $this->pdo->prepare("SELECT definition_json, code, is_active FROM process_definitions WHERE id = ?");
@@ -562,8 +613,21 @@ class WorkflowEngine {
     }
 
     public function getInstanceByDefId(int $personId, int $processDefinitionId): ?array {
-        $stmt = $this->pdo->prepare("SELECT * FROM process_instances WHERE `person_id` = ? AND `process_definition_id` = ?");
-        $stmt->execute([$personId, $processDefinitionId]);
+        $stmt_code = $this->pdo->prepare("SELECT code FROM process_definitions WHERE id = ?");
+        $stmt_code->execute([$processDefinitionId]);
+        $code = $stmt_code->fetchColumn();
+        
+        if (!$code) return null;
+        
+        $stmt = $this->pdo->prepare("
+            SELECT pi.* 
+            FROM process_instances pi
+            JOIN process_definitions pd ON pi.process_definition_id = pd.id
+            WHERE pi.person_id = ? AND pd.code = ?
+            ORDER BY pi.last_activity_at DESC, pi.id DESC
+            LIMIT 1
+        ");
+        $stmt->execute([$personId, $code]);
         $instance = $stmt->fetch(PDO::FETCH_ASSOC);
         return $instance ?: null;
     }
diff --git a/_get_instance_details.php b/_get_instance_details.php
index 185f1b8..cdf1440 100644
--- a/_get_instance_details.php
+++ b/_get_instance_details.php
@@ -54,6 +54,57 @@ $instance = $engine->getInstanceByDefId($person_id, $process_definition_id);
 <?php if ($instance): // INSTANCE EXISTS ?>
     <?php
     $instanceId = $instance['id'];
+    $isCompleted = in_array($instance['current_status'], ['completed', 'positive', 'negative', 'error']);
+    ?>
+    <?php if ($isCompleted): ?>
+        <div class="alert alert-info d-flex justify-content-between align-items-center">
+            <div>
+                <strong><?= t('modal.process_completed', 'Proces zakończony.') ?></strong> 
+                Obecny status: <?= htmlspecialchars($instance['current_status']) ?>.
+            </div>
+            <button id="startNewProcessBtn" class="btn btn-sm btn-primary" data-person-id="<?= $person_id ?>" data-process-id="<?= $process_definition_id ?>">
+                <?= t('modal.start_new_instance', 'Rozpocznij od nowa') ?>
+            </button>
+        </div>
+        <script>
+            document.getElementById('startNewProcessBtn')?.addEventListener('click', function() {
+                const personId = this.getAttribute('data-person-id');
+                const processId = this.getAttribute('data-process-id');
+                if (confirm('Czy na pewno chcesz rozpocząć nową instancję tego procesu? Dotychczasowa historia pozostanie, ale proces rozpocznie się od nowa.')) {
+                    fetch('_init_single_instance.php', {
+                        method: 'POST',
+                        headers: {
+                            'Content-Type': 'application/x-www-form-urlencoded',
+                        },
+                        body: 'person_id=' + personId + '&process_id=' + processId + '&force=1'
+                    })
+                    .then(response => response.json())
+                    .then(data => {
+                        if (data.success) {
+                            // Reload the modal content
+                            fetch('_get_instance_details.php?person_id=' + personId + '&process_id=' + processId)
+                                .then(response => response.text())
+                                .then(html => {
+                                    document.querySelector('#instanceModal .modal-body').innerHTML = html;
+                                    // Trigger custom event to re-attach handlers and update title
+                                    const event = new Event('instanceModalLoaded');
+                                    document.querySelector('#instanceModal .modal-body').dispatchEvent(event);
+                                    // Set a flag to refresh the matrix when the modal closes
+                                    window.matrixNeedsRefresh = true;
+                                });
+                        } else {
+                            alert('Błąd: ' + (data.error || 'Nieznany błąd'));
+                        }
+                    })
+                    .catch(error => {
+                        console.error('Error:', error);
+                        alert('Wystąpił błąd podczas uruchamiania nowej instancji.');
+                    });
+                }
+            });
+        </script>
+    <?php endif; ?>
+    <?php
     $definition = $process['definition_json'] ? json_decode($process['definition_json'], true) : null;
     $isChecklist = ($definition && isset($definition['type']) && $definition['type'] === 'checklist');
     $events = $engine->getEvents($instanceId);
diff --git a/_init_single_instance.php b/_init_single_instance.php
index 8aa87f0..3305205 100644
--- a/_init_single_instance.php
+++ b/_init_single_instance.php
@@ -42,7 +42,12 @@ if($deleteExisting === '1') {
 // 3. Checking if the person is eligible.
 // 4. Creating the instance if it doesn't exist.
 // It will throw specific exceptions (WorkflowNotFoundException, WorkflowNotAllowedException, WorkflowEligibilityException) which our ErrorHandler will turn into 404, 409, and 422 responses.
-$instance = $engine->getOrCreateInstanceByDefId($personId, $processDefinitionId, $userId);
+ = filter_input(INPUT_POST, 'force', FILTER_VALIDATE_INT);
+if ( === 1) {
+     = ->createNewInstance(, , );
+} else {
+     = ->getOrCreateInstanceByDefId(, , );
+}
 
 if ($instance) {
     echo json_encode(['success' => true, 'message' => 'Process initialized successfully.', 'instance_id' => $instance['id']]);
diff --git a/_save_process_definition.php b/_save_process_definition.php
index 0693dd5..b3ec95b 100644
--- a/_save_process_definition.php
+++ b/_save_process_definition.php
@@ -108,19 +108,36 @@ try {
 
         if (empty($processId)) {
             // Create new process
-            $sql = 'INSERT INTO process_definitions (name, code, definition_json, start_node_id, is_active) VALUES (?, ?, ?, ?, 1)';
+            $sql = 'INSERT INTO process_definitions (name, code, definition_json, start_node_id, is_active, version, is_latest) VALUES (?, ?, ?, ?, 1, 1, 1)';
             $params = [$name, $code, $definition_json, $start_node];
             $message = 'Process created successfully.';
+            $stmt = $pdo->prepare($sql);
+            $stmt->execute($params);
         } else {
-            // Update existing process
-            $is_active = isset($_POST['is_active']) ? (int)$_POST['is_active'] : 0;
-            $sql = 'UPDATE process_definitions SET name = ?, definition_json = ?, start_node_id = ?, is_active = ? WHERE id = ?';
-            $params = [$name, $definition_json, $start_node, $is_active, $processId];
-            $message = 'Process updated successfully.';
-        }
+            // "Update" existing process by creating a new version
+            $stmt_old = $pdo->prepare('SELECT code, version, sort_order, is_active FROM process_definitions WHERE id = ?');
+            $stmt_old->execute([$processId]);
+            $old = $stmt_old->fetch();
+            
+            if ($old) {
+                $is_active = isset($_POST['is_active']) ? (int)$_POST['is_active'] : $old['is_active'];
+                $new_version = $old['version'] + 1;
+                $db_code = $old['code'];
 
-        $stmt = $pdo->prepare($sql);
-        $stmt->execute($params);
+                // Mark all previous versions as not latest
+                $stmt_update = $pdo->prepare('UPDATE process_definitions SET is_latest = 0 WHERE code = ?');
+                $stmt_update->execute([$db_code]);
+
+                // Insert new version
+                $sql = 'INSERT INTO process_definitions (name, code, definition_json, start_node_id, is_active, version, supersedes_definition_id, is_latest, sort_order) VALUES (?, ?, ?, ?, ?, ?, ?, 1, ?)';
+                $params = [$name, $db_code, $definition_json, $start_node, $is_active, $new_version, $processId, $old['sort_order']];
+                $stmt = $pdo->prepare($sql);
+                $stmt->execute($params);
+                $message = 'Process updated successfully (new version created).';
+            } else {
+                throw new WorkflowRuleFailedException('Process not found.');
+            }
+        }
         if (isset($_SERVER['HTTP_ACCEPT']) && strpos($_SERVER['HTTP_ACCEPT'], 'application/json') !== false) {
             header('Content-Type: application/json');
             echo json_encode(['message' => $message]);
diff --git a/db/migrations/036_process_versioning.php b/db/migrations/036_process_versioning.php
new file mode 100644
index 0000000..5dda8e8
--- /dev/null
+++ b/db/migrations/036_process_versioning.php
@@ -0,0 +1,57 @@
+<?php
+
+function migrate_036($pdo) {
+    echo "Starting migration 036 (Process Versioning)...
+";
+
+    // 1. Process Definitions
+    $stmt = $pdo->query("SHOW INDEX FROM process_definitions WHERE Key_name = 'code'");
+    if ($stmt->fetch()) {
+        $pdo->exec("ALTER TABLE process_definitions DROP INDEX `code`");
+        echo "Dropped unique index on process_definitions.code.
+";
+    }
+
+    $stmt = $pdo->query("SHOW COLUMNS FROM process_definitions LIKE 'supersedes_definition_id'");
+    if (!$stmt->fetch()) {
+        $pdo->exec("ALTER TABLE process_definitions ADD COLUMN supersedes_definition_id INT(11) UNSIGNED NULL AFTER version");
+        echo "Added supersedes_definition_id to process_definitions.
+";
+    }
+
+    $stmt = $pdo->query("SHOW COLUMNS FROM process_definitions LIKE 'is_latest'");
+    if (!$stmt->fetch()) {
+        $pdo->exec("ALTER TABLE process_definitions ADD COLUMN is_latest TINYINT(1) NOT NULL DEFAULT 1 AFTER supersedes_definition_id");
+        echo "Added is_latest to process_definitions.
+";
+    }
+
+    $stmt = $pdo->query("SHOW INDEX FROM process_definitions WHERE Key_name = 'idx_code_latest_active'");
+    if (!$stmt->fetch()) {
+        $pdo->exec("ALTER TABLE process_definitions ADD INDEX idx_code_latest_active (code, is_latest, is_active)");
+        echo "Added index idx_code_latest_active on process_definitions.
+";
+    }
+
+    // Ensure existing rows are marked as latest properly (all existing should be latest)
+    // Nothing needed, default is 1.
+
+    // 2. Process Instances
+    $stmt = $pdo->query("SHOW INDEX FROM process_instances WHERE Key_name = 'person_process'");
+    if ($stmt->fetch()) {
+        $pdo->exec("ALTER TABLE process_instances DROP INDEX `person_process`");
+        echo "Dropped unique index on process_instances.person_process.
+";
+    }
+
+    $stmt = $pdo->query("SHOW INDEX FROM process_instances WHERE Key_name = 'idx_person_definition'");
+    if (!$stmt->fetch()) {
+        $pdo->exec("ALTER TABLE process_instances ADD INDEX idx_person_definition (person_id, process_definition_id)");
+        echo "Added index idx_person_definition on process_instances.
+";
+    }
+
+    echo "Migration 036 completed.
+";
+}
+
diff --git a/index.php b/index.php
index 9f3392d..4081cff 100644
--- a/index.php
+++ b/index.php
@@ -1392,6 +1392,13 @@ document.addEventListener('DOMContentLoaded', function () {
             }
         });
     }
+
+    instanceModalElement.addEventListener('hidden.bs.modal', function () {
+        if (window.matrixNeedsRefresh) {
+            window.location.reload();
+        }
+    });
 });
 </script>
+
 <?php include '_footer.php'; ?>
diff --git a/patch2.py b/patch2.py
new file mode 100644
index 0000000..a329ee5
--- /dev/null
+++ b/patch2.py
@@ -0,0 +1,17 @@
+import re
+
+with open('WorkflowEngine.php', 'r') as f:
+    content = f.read()
+
+target = """        $stmt = $this->pdo->prepare("SELECT * FROM process_instances WHERE `person_id` = ? AND `process_definition_id` = ?");
+        $stmt->execute([$personId, $processDefinitionId]);
+        $instance = $stmt->fetch(PDO::FETCH_ASSOC);"""
+
+replacement = """        $instance = $this->getInstanceByDefId($personId, $processDefinitionId);"""
+
+content = content.replace(target, replacement)
+
+with open('WorkflowEngine.php', 'w') as f:
+    f.write(content)
+
+print("Patched.")
diff --git a/patch_engine.py b/patch_engine.py
new file mode 100644
index 0000000..5fe00bd
--- /dev/null
+++ b/patch_engine.py
@@ -0,0 +1,71 @@
+import re
+
+with open('WorkflowEngine.php', 'r') as f:
+    content = f.read()
+
+content = content.replace(
+    'SELECT id, name, definition_json, is_active FROM process_definitions WHERE is_active = 1 ORDER BY sort_order, name',
+    'SELECT id, code, name, definition_json, is_active FROM process_definitions WHERE is_active = 1 AND is_latest = 1 ORDER BY sort_order, name'
+)
+
+content = content.replace(
+    "'name' => $def['name'],",
+    "'code' => $def['code'],\n                'name' => $def['name'],"
+)
+
+content = content.replace(
+    '$stmt_instances = $this->pdo->prepare("SELECT * FROM process__instances WHERE person_id IN ($placeholders)");\n            $stmt_instances->execute($person_ids);\n            $instances_data = $stmt_instances->fetchAll(PDO::FETCH_ASSOC);',
+    """
+$stmt_instances = $this->pdo->prepare(
+                SELECT pi.*, pd.code as process_code, pd.id as definition_actual_id
+                FROM process_instances pi
+                JOIN process_definitions pd ON pi.process_definition_id = pd.id
+                WHERE pi.person_id IN ($placeholders)
+                ORDER BY pi.last_activity_at DESC, pi.id DESC
+            ");
+            $stmt_instances->execute($person_ids);
+            $instances_data = $stmt_instances->fetchAll(PDO::FETCH_ASSOC);
+
+            // Map code to latest definition id
+            $codeToIdMap = [];
+            foreach ($definitions as $defId => $def) {
+                $codeToIdMap[$def['code']] = $defId;
+            }""")
+
+content = content.replace(
+    "$instances[$instance['person_id']][$def_id] = $enriched_instance;",
+    """
+// Use process_code to map to the latest active column
+                $code = $instance['process_code'] ?? null;
+                if ($code && isset($codeToIdMap[$code])) {
+                    $latestDefId = $codeToIdMap[$code];
+                    // Only keep the most recently active instance per code (since ordered by last_activity_at DESC)
+                    if (!isset($instances[$instance['person_id']][$latestDefId])) {
+                        $instances[$instance['person_id']][$latestDefId] = $enriched_instance;
+                    }
+                }""")
+
+content = re.sub(
+    r"public function getInstanceByDefId\(int \$personId, int \$processDefinitionId\): \?array \{.*?return \$instance \?: null;\s*\}",
+    """public function getInstanceByDefId(int $personId, int $processDefinitionId): ?array {
+        $stmt_code = $this->pdo->prepare("SELECT code FROM process_definitions WHERE id = ?");
+        $stmt_code->execute([$processDefinitionId]);
+        $code = $stmt_code->fetchColumn();
+        
+        if (!$code) return null;
+        
+        $stmt = $this->pdo->prepare("\n            SELECT pi.* \n            FROM process_instances pi\n            JOIN process_definitions pd ON pi.process_definition_id = pd.id\n            WHERE pi.person_id = ? AND pd.code = ?\n            ORDER BY pi.last_activity_at DESC, pi.id DESC\n            LIMIT 1\n        ");
+        $stmt->execute([$personId, $code]);
+        $instance = $stmt->fetch(PDO::FETCH_ASSOC);
+        return $instance ?: null;
+    }""",
+    content, flags=re.DOTALL
+)
+
+# Wait, checkEligibility needs to use the NEW version definition ID?
+# Actually checkEligibility uses $processDefinitionId which IS the new version's ID!
+
+with open('WorkflowEngine.php', 'w') as f:
+    f.write(content)
+
+print("Patched.")
\ No newline at end of file
diff --git a/patch_index.py b/patch_index.py
new file mode 100644
index 0000000..9505e09
--- /dev/null
+++ b/patch_index.py
@@ -0,0 +1,21 @@
+import re
+
+with open('index.php', 'r') as f:
+    content = f.read()
+
+patch_code = """
+    instanceModalElement.addEventListener('hidden.bs.modal', function () {
+        if (window.matrixNeedsRefresh) {
+            window.location.reload();
+        }
+    });
+});
+</script>
+"""
+
+content = content.replace("});\n</script>", patch_code)
+
+with open('index.php', 'w') as f:
+    f.write(content)
+
+print("Patched index.php")
diff --git a/patch_init.py b/patch_init.py
new file mode 100644
index 0000000..f66e74a
--- /dev/null
+++ b/patch_init.py
@@ -0,0 +1,59 @@
+import re
+
+with open('WorkflowEngine.php', 'r') as f:
+    content = f.read()
+
+new_method = """
+    public function createNewInstance(int $personId, int $processDefinitionId, int $userId, array $context = []): array {
+        if (!is_int($processDefinitionId) || $processDefinitionId <= 0) {
+            throw new InvalidArgumentException("processDefinitionId must be a positive integer.");
+        }
+        if (!is_int($personId) || $personId <= 0) {
+            throw new InvalidArgumentException("personId must be a positive integer.");
+        }
+
+        $stmt_def = $this->pdo->prepare("SELECT definition_json, code, is_active FROM process_definitions WHERE id = ?");
+        $stmt_def->execute([$processDefinitionId]);
+        $definition = $stmt_def->fetch(PDO::FETCH_ASSOC);
+
+        if (!$definition) {
+            throw new WorkflowNotFoundException("Process definition #$processDefinitionId not found.");
+        }
+
+        if (empty($definition['is_active'])) {
+            throw new WorkflowNotAllowedException("Process is not active and cannot be started.");
+        }
+
+        $eligibility = $this->checkEligibility($personId, $processDefinitionId, $context);
+        if (!$eligibility['is_eligible']) {
+            throw new WorkflowEligibilityException("Person is not eligible to start this process.", $eligibility['reasons']);
+        }
+
+        $definition_json = !empty($definition['definition_json']) ? json_decode($definition['definition_json'], true) : [];
+        $start_node = $definition_json['start_node_id'] ?? 'start';
+        $initial_data_map = $definition_json['initial_data'] ?? [];
+        $data_json = !empty($initial_data_map) ? json_encode($initial_data_map) : null;
+
+        $stmt = $this->pdo->prepare(
+            "INSERT INTO process_instances (person_id, process_definition_id, current_node_id, current_status, data_json, last_activity_at) VALUES (?, ?, ?, 'in_progress', ?, NOW())"
+        );
+        $stmt->execute([$personId, $processDefinitionId, $start_node, $data_json]);
+        $newInstanceId = $this->pdo->lastInsertId();
+
+        $this->logEvent($newInstanceId, 'process_started', 'Process started', $start_node, ['context' => $context], $userId);
+
+        $stmt = $this->pdo->prepare("SELECT * FROM process_instances WHERE id = ?");
+        $stmt->execute([$newInstanceId]);
+        return $stmt->fetch(PDO::FETCH_ASSOC);
+    }
+"
+
+content = content.replace(
+    'public function getOrCreateInstanceByDefId(int $personId, int $processDefinitionId, int $userId, array $context = []): ?array {',
+    new_method + '\n    public function getOrCreateInstanceByDefId(int $personId, int $processDefinitionId, int $userId, array $context = []): ?array {'
+)
+
+with open('WorkflowEngine.php', 'w') as f:
+    f.write(content)
+
+print("Patched.")
diff --git a/patch_modal.py b/patch_modal.py
new file mode 100644
index 0000000..853538d
--- /dev/null
+++ b/patch_modal.py
@@ -0,0 +1,73 @@
+import re
+
+with open('_get_instance_details.php', 'r') as f:
+    content = f.read()
+
+patch_code = """<?php if ($instance): // INSTANCE EXISTS ?>
+    <?php
+    $instanceId = $instance['id'];
+    $isCompleted = in_array($instance['current_status'], ['completed', 'positive', 'negative', 'error']);
+    ?>
+    <?php if ($isCompleted): ?>
+        <div class="alert alert-info d-flex justify-content-between align-items-center">
+            <div>
+                <strong><?= t('modal.process_completed', 'Proces zakończony.') ?></strong> 
+                Obecny status: <?= htmlspecialchars($instance['current_status']) ?>.
+            </div>
+            <button id="startNewProcessBtn" class="btn btn-sm btn-primary" data-person-id="<?= $person_id ?>" data-process-id="<?= $process_definition_id ?>">
+                <?= t('modal.start_new_instance', 'Rozpocznij od nowa') ?>
+            </button>
+        </div>
+        <script>
+            document.getElementById('startNewProcessBtn')?.addEventListener('click', function() {
+                const personId = this.getAttribute('data-person-id');
+                const processId = this.getAttribute('data-process-id');
+                if (confirm('Czy na pewno chcesz rozpocząć nową instancję tego procesu? Dotychczasowa historia pozostanie, ale proces rozpocznie się od nowa.')) {
+                    fetch('_init_single_instance.php', {
+                        method: 'POST',
+                        headers: {
+                            'Content-Type': 'application/x-www-form-urlencoded',
+                        },
+                        body: 'person_id=' + personId + '&process_id=' + processId + '&force=1'
+                    })
+                    .then(response => response.json())
+                    .then(data => {
+                        if (data.success) {
+                            // Reload the modal content
+                            fetch('_get_instance_details.php?person_id=' + personId + '&process_id=' + processId)
+                                .then(response => response.text())
+                                .then(html => {
+                                    document.getElementById('instanceModalBody').innerHTML = html;
+                                    // Trigger custom event to re-attach handlers and update title
+                                    const event = new Event('instanceModalLoaded');
+                                    document.getElementById('instanceModalBody').dispatchEvent(event);
+                                    // Set a flag to refresh the matrix when the modal closes
+                                    window.matrixNeedsRefresh = true;
+                                });
+                        } else {
+                            alert('Błąd: ' + (data.error || 'Nieznany błąd'));
+                        }
+                    })
+                    .catch(error => {
+                        console.error('Error:', error);
+                        alert('Wystąpił błąd podczas uruchamiania nowej instancji.');
+                    });
+                }
+            });
+        </script>
+    <?php endif; ?>
+    <?php
+    $definition = $process['definition_json'] ? json_decode($process['definition_json'], true) : null;"""
+
+content = content.replace(
+    """<?php if ($instance): // INSTANCE EXISTS ?>
+    <?php
+    $instanceId = $instance['id'];
+    $definition = $process['definition_json'] ? json_decode($process['definition_json'], true) : null;""",
+    patch_code
+)
+
+with open('_get_instance_details.php', 'w') as f:
+    f.write(content)
+
+print("Patched.")
diff --git a/patch_save.py b/patch_save.py
new file mode 100644
index 0000000..4a7bf65
--- /dev/null
+++ b/patch_save.py
@@ -0,0 +1,60 @@
+import re
+
+with open('_save_process_definition.php', 'r') as f:
+    content = f.read()
+
+old_update_logic = """        if (empty($processId)) {
+            // Create new process
+            $sql = 'INSERT INTO process_definitions (name, code, definition_json, start_node_id, is_active) VALUES (?, ?, ?, ?, 1)';
+            $params = [$name, $code, $definition_json, $start_node];
+            $message = 'Process created successfully.';
+        } else {
+            // Update existing process
+            $is_active = isset($_POST['is_active']) ? (int)$_POST['is_active'] : 0;
+            $sql = 'UPDATE process_definitions SET name = ?, definition_json = ?, start_node_id = ?, is_active = ? WHERE id = ?';
+            $params = [$name, $definition_json, $start_node, $is_active, $processId];
+            $message = 'Process updated successfully.';
+        }
+
+        $stmt = $pdo->prepare($sql);
+        $stmt->execute($params);"""
+
+new_update_logic = """        if (empty($processId)) {
+            // Create new process
+            $sql = 'INSERT INTO process_definitions (name, code, definition_json, start_node_id, is_active, version, is_latest) VALUES (?, ?, ?, ?, 1, 1, 1)';
+            $params = [$name, $code, $definition_json, $start_node];
+            $message = 'Process created successfully.';
+            $stmt = $pdo->prepare($sql);
+            $stmt->execute($params);
+        } else {
+            // "Update" existing process by creating a new version
+            $stmt_old = $pdo->prepare('SELECT code, version, sort_order, is_active FROM process_definitions WHERE id = ?');
+            $stmt_old->execute([$processId]);
+            $old = $stmt_old->fetch();
+            
+            if ($old) {
+                $is_active = isset($_POST['is_active']) ? (int)$_POST['is_active'] : $old['is_active'];
+                $new_version = $old['version'] + 1;
+                $db_code = $old['code'];
+
+                // Mark all previous versions as not latest
+                $stmt_update = $pdo->prepare('UPDATE process_definitions SET is_latest = 0 WHERE code = ?');
+                $stmt_update->execute([$db_code]);
+
+                // Insert new version
+                $sql = 'INSERT INTO process_definitions (name, code, definition_json, start_node_id, is_active, version, supersedes_definition_id, is_latest, sort_order) VALUES (?, ?, ?, ?, ?, ?, ?, 1, ?)';
+                $params = [$name, $db_code, $definition_json, $start_node, $is_active, $new_version, $processId, $old['sort_order']];
+                $stmt = $pdo->prepare($sql);
+                $stmt->execute($params);
+                $message = 'Process updated successfully (new version created).';
+            } else {
+                throw new WorkflowRuleFailedException('Process not found.');
+            }
+        }"""
+
+content = content.replace(old_update_logic, new_update_logic)
+
+with open('_save_process_definition.php', 'w') as f:
+    f.write(content)
+
+print("Patched.")
diff --git a/process_definitions.php b/process_definitions.php
index 04b054d..69f7535 100644
--- a/process_definitions.php
+++ b/process_definitions.php
@@ -4,7 +4,7 @@ require_once 'WorkflowEngine.php';
 $workflowEngine = new WorkflowEngine();
 // TODO: Create a method in WorkflowEngine to get all process definitions
 $pdo = db();
-$stmt = $pdo->query("SELECT * FROM process_definitions WHERE is_active = 1 ORDER BY sort_order, name");
+$stmt = $pdo->query("SELECT * FROM process_definitions WHERE is_active = 1 AND is_latest = 1 ORDER BY sort_order, name");
 $processes = $stmt->fetchAll(PDO::FETCH_ASSOC);
 
 ?>
diff --git a/temp_matrix.php b/temp_matrix.php
new file mode 100644
index 0000000..2568970
--- /dev/null
+++ b/temp_matrix.php
@@ -0,0 +1,187 @@
+        public function getDashboardMatrix(?string $searchTerm = null, ?int $groupId = null, ?int $activeProcessDefinitionId = null, ?int $meetingFilterGroupId = null, ?string $meetingFilterDatetime = null): array {
+        // 1. Base query for people
+        $sql_people = "SELECT p.*, bg.name as bni_group_name FROM people p LEFT JOIN bni_groups bg ON p.bni_group_id = bg.id";
+        $params = [];
+        $where_clauses = [];
+
+        // 2. Add filter conditions
+        if ($searchTerm) {
+            $where_clauses[] = "(p.first_name LIKE :search OR p.last_name LIKE :search OR p.company_name LIKE :search OR p.email LIKE :search)";
+            $params[':search'] = '%' . $searchTerm . '%';
+        }
+
+        if ($groupId) {
+            $where_clauses[] = "p.bni_group_id = :group_id";
+            $params[':group_id'] = $groupId;
+        }
+        
+        if ($activeProcessDefinitionId) {
+            $terminal_statuses = ['positive', 'negative', 'completed', 'error', 'inactive'];
+            $in_clause = implode(',', array_map([$this->pdo, 'quote'], $terminal_statuses));
+            
+            $sql_people .= " INNER JOIN process_instances pi ON p.id = pi.person_id";
+            $where_clauses[] = "pi.process_definition_id = :active_process_id AND (pi.current_status IS NOT NULL AND pi.current_status NOT IN ($in_clause))";
+            $params[':active_process_id'] = $activeProcessDefinitionId;
+        }
+
+        if ($meetingFilterGroupId && $meetingFilterDatetime) {
+            $meetingId = $this->getOrCreateMeeting($meetingFilterGroupId, $meetingFilterDatetime);
+            $sql_people .= " INNER JOIN meeting_attendance ma ON p.id = ma.person_id";
+            $where_clauses[] = "ma.meeting_id = :meeting_id";
+            $where_clauses[] = "ma.attendance_status IN ('present', 'absent', 'substitute')";
+            $params[':meeting_id'] = $meetingId;
+        }
+
+        if (!empty($where_clauses)) {
+            $sql_people .= " WHERE " . implode(" AND ", $where_clauses);
+        }
+
+        $sql_people .= " ORDER BY p.last_name, p.first_name";
+
+        // 3. Execute query to get filtered people
+        $stmt_people = $this->pdo->prepare($sql_people);
+        $stmt_people->execute($params);
+        $people = $stmt_people->fetchAll(PDO::FETCH_ASSOC);
+
+        // 4. Fetch all process definitions with their JSON
+        $stmt_defs = $this->pdo->prepare("SELECT id, code, name, definition_json, is_active FROM process_definitions WHERE is_active = 1 AND is_latest = 1 ORDER BY sort_order, name");
+        $stmt_defs->execute();
+        $process_definitions_raw = $stmt_defs->fetchAll(PDO::FETCH_ASSOC);
+        
+        $definitions = [];
+        $definition_map = [];
+        foreach ($process_definitions_raw as $def) {
+            $definitions[$def['id']] = [
+                'id' => $def['id'],
+                'code' => $def['code'],
+                'name' => $def['name'],
+                'is_active' => $def['is_active']
+            ];
+            $definition_map[$def['id']] = !empty($def['definition_json']) ? json_decode($def['definition_json'], true) : null;
+        }
+
+        // 5. Fetch instances ONLY for the filtered people
+        $instances = [];
+        $person_ids = array_column($people, 'id');
+        if (!empty($person_ids)) {
+            $placeholders = implode(',', array_fill(0, count($person_ids), '?'));
+            $stmt_instances = $this->pdo->prepare("SELECT * FROM process_instances WHERE person_id IN ($placeholders)");
+            $stmt_instances->execute($person_ids);
+            $instances_data = $stmt_instances->fetchAll(PDO::FETCH_ASSOC);
+        
+            foreach ($instances_data as $instance) {
+                $enriched_instance = $instance;
+                $def_id = $instance['process_definition_id'];
+                $node_id = $instance['current_node_id'];
+    
+                $definition = $definition_map[$def_id] ?? null;
+    
+                if ($definition && isset($definition['type']) && $definition['type'] === 'checklist') {
+                    $tasks = $definition['tasks'] ?? [];
+                    $instanceData = $instance['data_json'] ? json_decode($instance['data_json'], true) : [];
+                    $totalTasks = count($tasks);
+                    $completedTasks = 0;
+                    if(is_array($instanceData)) {
+                        foreach ($tasks as $task) {
+                            if (!empty($instanceData[$task['code']])) {
+                                $completedTasks++;
+                            }
+                        }
+                    }
+    
+                    if ($totalTasks > 0 && $completedTasks === $totalTasks) {
+                        $status = 'completed';
+                    } elseif ($completedTasks > 0) {
+                        $status = 'in_progress';
+                    } else {
+                        $status = 'inactive';
+                    }
+                    $enriched_instance['computed_status'] = $status;
+                    $enriched_instance['computed_reason'] = "$completedTasks/$totalTasks completed";
+                    $enriched_instance['computed_next_step'] = ''; 
+                } else if ($definition && isset($definition['nodes'][$node_id])) {
+                    $node_info = $definition['nodes'][$node_id];
+                    $enriched_instance['computed_status'] = $node_info['ui_hints']['status'] ?? $instance['current_status'];
+                    $enriched_instance['computed_reason'] = $node_info['ui_hints']['reason'] ?? $instance['current_reason'];
+                    $enriched_instance['computed_next_step'] = $node_info['ui_hints']['next_step'] ?? $instance['suggested_next_step'];
+                } else {
+                    $enriched_instance['computed_status'] = $instance['current_status'];
+                    $enriched_instance['computed_reason'] = $instance['current_reason'];
+                    $enriched_instance['computed_next_step'] = $instance['suggested_next_step'];
+                }
+                
+                $instances[$instance['person_id']][$def_id] = $enriched_instance;
+            }
+        }
+
+        // 6. Fetch ancillary data
+        $stmt_functions = $this->pdo->query("SELECT * FROM functions ORDER BY display_order");
+        $all_functions = $stmt_functions->fetchAll(PDO::FETCH_ASSOC);
+
+        $stmt_person_functions = $this->pdo->query("SELECT user_id, function_id FROM user_functions");
+        $person_functions_map = [];
+        while ($row = $stmt_person_functions->fetch(PDO::FETCH_ASSOC)) {
+            $person_functions_map[$row['user_id']][] = $row['function_id'];
+        }
+
+        $stmt_bni_groups = $this->pdo->query("SELECT * FROM bni_groups ORDER BY name");
+        $bni_groups = $stmt_bni_groups->fetchAll(PDO::FETCH_ASSOC);
+
+        // 7. Fetch Spotkania columns (upcoming meetings)
+        $today = date('Y-m-d H:i:s');
+        $stmt_meetings = $this->pdo->prepare("
+            WITH RankedMeetings AS (
+                SELECT
+                    bg.id as group_id,
+                    bg.name as group_name,
+                    ce.start_datetime,
+                    ROW_NUMBER() OVER(PARTITION BY bg.id ORDER BY ce.start_datetime) as rn
+                FROM bni_groups bg
+                JOIN calendar_event_groups ceg ON bg.id = ceg.bni_group_id
+                JOIN calendar_events ce ON ceg.calendar_event_id = ce.id
+                WHERE ce.start_datetime >= :today
+            )
+            SELECT group_id, group_name, start_datetime
+            FROM RankedMeetings
+            WHERE rn <= 3
+            ORDER BY group_id, start_datetime;
+        ");
+        $stmt_meetings->execute(['today' => $today]);
+        $upcoming_meetings_flat = $stmt_meetings->fetchAll(PDO::FETCH_ASSOC);
+
+        $spotkania_cols = [];
+        foreach ($upcoming_meetings_flat as $meeting) {
+            $spotkania_cols[$meeting['group_id']]['group_id'] = $meeting['group_id'];
+            $spotkania_cols[$meeting['group_id']]['group_name'] = $meeting['group_name'];
+            $spotkania_cols[$meeting['group_id']]['meetings'][] = $meeting['start_datetime'];
+        }
+
+
+        return [
+            'people' => $people,
+            'definitions' => array_values($definitions),
+            'instances' => $instances,
+            'all_functions' => $all_functions,
+            'person_functions_map' => $person_functions_map,
+            'bni_groups' => $bni_groups,
+            'spotkania_cols' => $spotkania_cols, // Add this to the return array
+        ];
+    }
+
+        public function startProcess(string $processCode, int $personId, int $userId): int {
+        $inTransaction = $this->pdo->inTransaction();
+        if (!$inTransaction) { $this->pdo->beginTransaction(); }
+        try {
+            // 1. Find active process definition by code.
+            $stmt_def = $this->pdo->prepare("SELECT * FROM process_definitions WHERE code = ? AND is_active = 1");
+            $stmt_def->execute([$processCode]);
+            $definition = $stmt_def->fetch(PDO::FETCH_ASSOC);
+
+            if (!$definition) {
+                // If no process definition is found, check if there is a definition for a checklist
+                $stmt_def = $this->pdo->prepare("SELECT * FROM process_definitions WHERE id = ?");
+                $stmt_def->execute([$processCode]);
+                $definition = $stmt_def->fetch(PDO::FETCH_ASSOC);
+
+                if (!$definition) {
+                    throw new WorkflowNotFoundException("Process definition with code or id '$processCode' not found.");