diff --git a/addons/sale_timesheet/models/product.py b/addons/sale_timesheet/models/product.py
index b3035565c9b..2f3c86d562f 100644
--- a/addons/sale_timesheet/models/product.py
+++ b/addons/sale_timesheet/models/product.py
@@ -20,4 +20,3 @@ class ProductTemplate(models.Model):
             self.track_service = 'timesheet'
         else:
             self.track_service = 'manual'
-
diff --git a/addons/sale_timesheet/models/sale_order.py b/addons/sale_timesheet/models/sale_order.py
index a11e320a645..da90a057137 100644
--- a/addons/sale_timesheet/models/sale_order.py
+++ b/addons/sale_timesheet/models/sale_order.py
@@ -58,16 +58,9 @@ class SaleOrder(models.Model):
 
     @api.multi
     def action_confirm(self):
+        """ On SO confirmation, some lines should generate a task or a project. """
         result = super(SaleOrder, self).action_confirm()
-        for order in self:
-            if not order.project_project_id:
-                for line in order.order_line:
-                    if line.product_id.track_service == 'timesheet':
-                        if not order.project_id:
-                            order._create_analytic_account(prefix=line.product_id.default_code or None)
-                        order.project_id.project_create({'name': order.project_id.name})
-                        break
-            order.order_line.filtered(lambda line: line.is_service_task)._timesheet_find_task()
+        self.order_line._timesheet_service_generation()
         return result
 
     @api.multi
@@ -133,22 +126,25 @@ class SaleOrder(models.Model):
 class SaleOrderLine(models.Model):
     _inherit = "sale.order.line"
 
-    task_id = fields.Many2one('project.task', 'Task')
-    is_service_task = fields.Boolean("Will create a task", compute='_compute_is_service_task')
+    task_id = fields.Many2one('project.task', 'Task', help="Task generated by the sales order item")
+    is_service = fields.Boolean("Is service", compute='_compute_is_service', help="Sales Order item should generate a task and/or a project, depending on the product settings.")
 
     @api.multi
-    def _compute_is_service_task(self):
+    def _compute_is_service(self):
         for so_line in self:
-            so_line.is_service_task = so_line.product_id.type == 'service' and so_line.product_id.track_service == 'task'
+            so_line.is_service = so_line.product_id.type == 'service' and so_line.product_id.track_service in ['task', 'timesheet']
 
     @api.model
     def create(self, values):
         line = super(SaleOrderLine, self).create(values)
-        if line.state == 'sale' and not line.order_id.project_id and line.product_id.track_service in ['timesheet', 'task']:
-            line.order_id._create_analytic_account()
-            line._timesheet_find_task()
+        if line.state == 'sale':
+            line._timesheet_service_generation()
         return line
 
+    ###########################################
+    ### Analytic : auto recompute delivered quantity
+    ###########################################
+
     def _timesheet_compute_delivered_quantity_domain(self):
         # TODO JEM: avoid increment delivered for all AAL or just timesheet ?
         # see nim commit https://github.com/odoo/odoo/commit/21fbb9776a5fbd1838b189f1f7cf8c5d40663e14
@@ -161,6 +157,10 @@ class SaleOrderLine(models.Model):
         timesheet_domain = self._timesheet_compute_delivered_quantity_domain()
         return expression.OR([domain, timesheet_domain])
 
+    ###########################################
+    ## Service : Project and task generation
+    ###########################################
+
     def _convert_qty_company_hours(self):
         company_time_uom_id = self.env.user.company_id.project_time_mode_id
         if self.product_uom.id != company_time_uom_id.id and self.product_uom.category_id.id == company_time_uom_id.category_id.id:
@@ -170,18 +170,19 @@ class SaleOrderLine(models.Model):
         return planned_hours
 
     def _timesheet_find_project(self):
+        self.ensure_one()
         Project = self.env['project.project']
         project = self.product_id.with_context(force_company=self.company_id.id).project_id
         if not project:
             # find the project corresponding to the analytic account of the sales order
             account = self.order_id.project_id
             if not account:
-                self.order_id._create_analytic_account()
+                self.order_id._create_analytic_account(prefix=self.product_id.default_code or None)
                 account = self.order_id.project_id
             project = Project.search([('analytic_account_id', '=', account.id)], limit=1)
             if not project:
-                project_id = account.project_create({'name': account.name})
-                project = Project.browse(project_id)
+                project_id = account.sudo().project_create({'name': account.name})
+                project = Project.sudo().browse(project_id)
         return project
 
     def _timesheet_create_task_prepare_values(self):
@@ -243,3 +244,14 @@ class SaleOrderLine(models.Model):
                 task = so_line._timesheet_create_task()[so_line.id]
             result[so_line.id] = task
         return result
+
+    @api.multi
+    def _timesheet_service_generation(self):
+        """ For service lines, create the task or the project. If already exists, it simply links
+            the existing one to the line.
+        """
+        for so_line in self.filtered(lambda sol: sol.is_service):
+            if so_line.product_id.track_service == 'task':
+                so_line._timesheet_find_task()
+            if so_line.product_id.track_service == 'timesheet':
+                so_line._timesheet_find_project()