diff --git a/models/pos_prep_state.py b/models/pos_prep_state.py
index d279630..25b4130 100644
--- a/models/pos_prep_state.py
+++ b/models/pos_prep_state.py
@@ -68,7 +68,7 @@ class PosPreparationState(models.Model):
                     ('prep_display_id', '=', display_id)
                 ], limit=1)
                 if line_report:
-                    line_report.unlink()
+                    line_report.write({'state': 'in_prep'})
 
                 order_report = KdsOrderReport.search([
                     ('pos_order_id', '=', order_id),
@@ -76,34 +76,22 @@ class PosPreparationState(models.Model):
                 ], limit=1)
 
                 if order_report:
-                    res = KdsLineReport._read_group(
-                        [('pos_order_id', '=', order_id), ('prep_display_id', '=', display_id)],
-                        aggregates=['completion_time:max']
-                    )
-                    max_comp_time = res[0][0] if res else 0
-                    if max_comp_time == 0:
-                        order_report.unlink()
-                    else:
-                        order_report.write({'completion_time': max_comp_time})
+                    order_report.write({'state': 'in_prep'})
                 return
 
             # --- Completed ---
-            # Use a slightly larger epsilon for -1 check to be safe with float/int conversions if any
             prep_time = order_line.preparation_time
             svc_time = order_line.service_time
 
             # Fallback timing logic
             if prep_time == -1:
                 if old_last_stage_change:
-                    # If we have the old timestamp, it means we spent time in the previous stage
                     prep_time = int(compute_seconds_since(old_last_stage_change))
                 else:
-                    # Otherwise use the current stage entry time
                     prep_time = int(compute_seconds_since(pdis_state.last_stage_change))
             
             if svc_time == -1:
                 if is_completed and stage.id == last_stage_id and old_last_stage_change:
-                    # If moving to last stage, service time is time spent in previous stage
                     svc_time = int(compute_seconds_since(old_last_stage_change))
                 else:
                     svc_time = 0
@@ -112,8 +100,10 @@ class PosPreparationState(models.Model):
             svc_time = max(0, svc_time)
             comp_time = prep_time + svc_time
 
-            _logger.info("KDS Completed: Order %s, Line %s: Prep=%ss, Svc=%ss, Total=%ss", 
-                         order_name, order_line.product_id.name, prep_time, svc_time, comp_time)
+            line_report = KdsLineReport.search([
+                ('pos_order_line_id', '=', order_line.id),
+                ('prep_display_id', '=', display_id)
+            ], limit=1)
 
             vals = {
                 'pos_order_id': order_id,
@@ -124,36 +114,57 @@ class PosPreparationState(models.Model):
                 'service_time': svc_time,
                 'completion_time': comp_time,
                 'completion_datetime': fields.Datetime.now(),
+                'state': 'done',
             }
 
-            line_report = KdsLineReport.search([
-                ('pos_order_line_id', '=', order_line.id),
-                ('prep_display_id', '=', display_id)
-            ], limit=1)
-
             if line_report:
-                line_report.write(vals)
+                # Accumulate if it was already existing (e.g. from a previous completion before reset)
+                # Note: We only accumulate if the current session's time is valid.
+                new_prep = line_report.preparation_time + prep_time
+                new_svc = line_report.service_time + svc_time
+                new_comp = new_prep + new_svc
+                
+                _logger.info("KDS Re-Completed (Accumulating): Order %s, Line %s: %ss + %ss = %ss", 
+                             order_name, order_line.product_id.name, line_report.completion_time, comp_time, new_comp)
+                
+                line_report.write({
+                    'preparation_time': new_prep,
+                    'service_time': new_svc,
+                    'completion_time': new_comp,
+                    'completion_datetime': vals['completion_datetime'],
+                    'state': 'done',
+                })
+                # Update local comp_time for order report update below
+                comp_time = new_comp
             else:
+                _logger.info("KDS Completed: Order %s, Line %s: Prep=%ss, Svc=%ss, Total=%ss", 
+                             order_name, order_line.product_id.name, prep_time, svc_time, comp_time)
                 KdsLineReport.create(vals)
 
-            # Update Order Report - Optimized to avoid _read_group inside loops
+            # Update Order Report
             order_report = KdsOrderReport.search([
                 ('pos_order_id', '=', order_id),
                 ('prep_display_id', '=', display_id)
             ], limit=1)
 
             if order_report:
-                # Only update if the new completion time is greater, or if it's been some time
-                if comp_time > order_report.completion_time:
+                # Update state and accumulate/max time
+                # We use the max completion time across all lines of this order for this display.
+                # If we just updated a line to 219s, and order report was 204s, it becomes 219s.
+                if comp_time > order_report.completion_time or order_report.state != 'done':
                     order_report.write({
-                        'completion_time': comp_time,
+                        'completion_time': max(comp_time, order_report.completion_time),
+                        'state': 'done',
                         'completion_datetime': vals['completion_datetime'],
                     })
             else:
                 KdsOrderReport.create({
                     'pos_order_id': order_id,
                     'prep_display_id': display_id,
+                    'preparation_time': prep_time, # Simplified: will be updated by other lines if needed
+                    'service_time': svc_time,
                     'completion_time': comp_time,
+                    'state': 'done',
                     'completion_datetime': vals['completion_datetime'],
                 })