diff --git a/project_task_line/__manifest__.py b/project_task_line/__manifest__.py
index d8023b12..6db1ed20 100644
--- a/project_task_line/__manifest__.py
+++ b/project_task_line/__manifest__.py
@@ -1,6 +1,6 @@
 {
     'name': 'Project Task Lines',
-    'version': '16.0.1.0.0',
+    'version': '17.0.1.0.0',
     'author': 'Hibou Corp. <hello@hibou.io>',
     'website': 'https://hibou.io/',
     'license': 'AGPL-3',
diff --git a/project_task_line/migrations/17.0.1.0.0/pre-migration.py b/project_task_line/migrations/17.0.1.0.0/pre-migration.py
new file mode 100644
index 00000000..85d8bd0c
--- /dev/null
+++ b/project_task_line/migrations/17.0.1.0.0/pre-migration.py
@@ -0,0 +1,14 @@
+def migrate(cr, installed_version):
+    cr.execute(
+        """
+        ALTER TABLE project_task_line
+        ADD COLUMN IF NOT EXISTS state VARCHAR
+        """,
+    )
+    cr.execute(
+        """
+        UPDATE project_task_line
+        SET state = kanban_state
+        WHERE kanban_state IN ('done', 'blocked')
+        """,
+    )
diff --git a/project_task_line/models/project.py b/project_task_line/models/project.py
index 3557f69c..1a467a7f 100644
--- a/project_task_line/models/project.py
+++ b/project_task_line/models/project.py
@@ -5,32 +5,6 @@ class ProjectTask(models.Model):
     _inherit = 'project.task'
 
     line_ids = fields.One2many('project.task.line', 'task_id', string='Todo List')
-    subtask_count_done = fields.Integer(compute='_compute_subtask_count', string="Sub-task Done count")
-
-    @api.depends('child_ids')
-    def _compute_subtask_count(self):
-        for task in self:
-            subtasks = task._get_all_subtasks()
-            task.subtask_count = len(subtasks)
-            task.subtask_count_done = len(subtasks.filtered(lambda t: t.is_closed))
-    
-    def action_subtask(self):
-        action = self.env.ref('project.action_view_all_task').sudo().read()[0]
-
-        # display all subtasks of current task
-        action['domain'] = [('id', 'child_of', self.id), ('id', '!=', self.id)]
-
-        ctx = dict(self.env.context)
-        ctx = {k: v for k, v in ctx.items() if not k.startswith('search_default_')}
-        ctx.update({
-            'default_name': self.env.context.get('name', self.name) + ':',
-            'default_parent_id': self.id,  # will give default subtask field in `default_get`
-            'default_company_id': self.env.company.id,
-        })
-
-        action['context'] = ctx
-
-        return action
 
 
 class ProjectTaskLine(models.Model):
@@ -40,19 +14,19 @@ class ProjectTaskLine(models.Model):
 
     task_id = fields.Many2one('project.task', required=True)
     name = fields.Char(string='Name')
-    user_id = fields.Many2one('res.users', string='User')
+    user_id = fields.Many2one(
+        'res.users', string='Completed By', 
+        context={'active_test': False}, 
+        compute='_compute_user_id', 
+        store=True, readonly=False, precompute=True,
+    )
     sequence = fields.Integer(string='Sequence')
-    kanban_state = fields.Selection([
-        ('normal', ''),
+    state = fields.Selection([
         ('done', 'Done'),
-        ('blocked', 'Blocked')], string='State',
-        copy=False, default='normal', required=True,
-        help="A task's kanban state indicates special situations affecting it:\n"
-             " * Blank is the default situation\n"
-             " * Blocked indicates something is preventing the progress of this task\n"
-             " * Done indicates the task is complete")
+        ('blocked', 'Blocked'),
+    ], string='State', copy=False)
 
-    @api.onchange('kanban_state')
-    def _onchange_kanban_state(self):
-        if self.kanban_state == 'done':
-            self.user_id = self.env.user
+    @api.depends('state')
+    def _compute_user_id(self):
+        for line in self.filtered(lambda l: l.state == 'done' and not l.user_id):
+            line.user_id = self.env.user
diff --git a/project_task_line/views/project_views.xml b/project_task_line/views/project_views.xml
index c7614426..8df89a1f 100644
--- a/project_task_line/views/project_views.xml
+++ b/project_task_line/views/project_views.xml
@@ -5,24 +5,21 @@
         <field name="model">project.task</field>
         <field name="inherit_id" ref="project.view_task_form2" />
         <field name="arch" type="xml">
-            <xpath expr="//div[@name='button_box']" position="inside">
-                <button name="action_subtask" type="object" class="oe_stat_button" icon="fa-tasks" attrs="{'invisible' : ['|', ('allow_subtasks', '=', False), ('id', '=', False)]}" context="{'default_user_ids': user_ids, 'default_parent_id': id, 'default_project_id': project_id}">
-                    <span class="o_stat_value"><field name="subtask_count_done" widget="statinfo" nolabel="1"/> / <field name="subtask_count" widget="statinfo" nolabel="1"/></span>
-                    <span class="o_stat_text">Sub-Tasks</span>
-                </button>
+            <xpath expr="//button[@name='%(project.project_task_action_sub_task)d']" position="attributes">
+                <attribute name="context">{'default_name': name + ':', 'default_user_ids': user_ids, 'default_project_id': project_id, 'default_milestone_id': milestone_id, 'subtask_action': True}</attribute>
             </xpath>
             <xpath expr="//page[@name='description_page']" position="after">
                 <page name="task_lines" string="Todo List">
-                    <field name="line_ids" widget="one2many_list" context="{'default_task_id': id}">
+                    <field name="line_ids" context="{'default_task_id': active_id}">
                         <tree editable="bottom">
                             <field name="sequence" widget="handle"/>
                             <field name="name"/>
-                            <field name="kanban_state" widget="selection" string="Status"/>
-                            <field name="user_id" string="Completed by" options="{'no_create': True, 'no_create_edit': True, 'no_open': True}"/>
+                            <field name="state" widget="selection"/>
+                            <field name="user_id" widget="many2one_avatar_user" domain="[('share', '=', False), ('active', '=', True)]"/>
                         </tree>
                     </field>
                 </page>
             </xpath>
         </field>
     </record>
-</odoo>
\ No newline at end of file
+</odoo>