Building the Custom Module

Initial Design

We started by analyzing IATF 16949 requirements and mapping them to Odoo's data model. The solution required extending two core models: mrp.production (manufacturing orders) and quality.check (quality inspections). We also needed new models for equipment tracking and process parameter logging.

Our first attempt used Odoo Studio to add custom fields. This worked for simple data capture but couldn't handle complex workflows like multi-level approvals or automated audit trail generation. We needed Python code.

Module Development

We created a custom module called multiprocess_quality_control. The module extended existing Odoo models and added new ones for compliance tracking.

python
from odoo import models, fields, api

class QualityCheckMultiProcess(models.Model):
    _inherit = 'quality.check'

    # Manufacturing process fields
    manufacturing_process = fields.Selection([
        ('injection_molding', 'Injection Molding'),
        ('3d_printing', '3D Printing'),
        ('cnc_machining', 'CNC Machining'),
        ('reduction_printing', 'Reduction Printing')
    ], string='Manufacturing Process', required=True)
    material_lot = fields.Char(string='Material Lot Number')
    customer_spec_id = fields.Char(string='Customer Specification ID')
    equipment_id = fields.Many2one('manufacturing.equipment', string='Equipment')
    process_temperature = fields.Float(string='Temperature (°C)')
    process_pressure = fields.Float(string='Pressure (bar)')
    cycle_time = fields.Float(string='Cycle Time (seconds)')
    analyst_signature = fields.Many2one('res.users', string='Analyst')
    supervisor_signature = fields.Many2one('res.users', string='Supervisor')
    qm_signature = fields.Many2one('res.users', string='Quality Manager')
    signature_date = fields.Datetime(string='Signature Date')

    @api.constrains('analyst_signature', 'supervisor_signature')
    def _check_signatures(self):
        for record in self:
            if record.quality_state == 'pass' and not record.supervisor_signature:
                raise ValidationError('Supervisor signature required for approval')
```
</code></pre>

<p>The code extends quality.check with automotive industry-required fields. The <a href="https://www.odoo.com/documentation/16.0/developer/reference/backend/orm.html#odoo.api.constrains" target="_blank">constraint</a> ensures supervisor approval before marking checks as passed. This enforces the <a href="https://www.aiag.org/training-and-resources/manuals" target="_blank">two-person rule</a> required by IATF 16949 regulations.</p>

<h3>Equipment and Process Tracking</h3>

<p>We created a new model to track manufacturing equipment and process parameters.</p>

<pre><code>
python
class ManufacturingEquipment(models.Model):
    _name = &#039;manufacturing.equipment&#039;
    _description = &#039;Manufacturing Equipment&#039;

    name = fields.Char(string=&#039;Equipment ID&#039;, required=True)
    equipment_type = fields.Selection([
        (&#039;injection_mold&#039;, &#039;Injection Molding Machine&#039;),
        (&#039;3d_printer&#039;, &#039;3D Printer&#039;),
        (&#039;cnc_machine&#039;, &#039;CNC Machine&#039;),
        (&#039;reduction_printer&#039;, &#039;Reduction Printer&#039;)
    ], required=True)
    last_maintenance = fields.Date(string=&#039;Last Maintenance&#039;)
    next_maintenance = fields.Date(string=&#039;Next Maintenance&#039;, compute=&#039;_compute_next_maintenance&#039;)
    maintenance_interval = fields.Integer(string=&#039;Maintenance Interval (days)&#039;, default=90)

    @api.depends(&#039;last_maintenance&#039;, &#039;maintenance_interval&#039;)
    def _compute_next_maintenance(self):
        for record in self:
            if record.last_maintenance:
                record.next_maintenance = record.last_maintenance + timedelta(days=record.maintenance_interval)
```

This model tracks equipment maintenance status. The computed field automatically calculates when maintenance is due, preventing use of unmaintained equipment.

Audit Trail Implementation

IATF 16949 requires complete audit trails showing who changed what and when. We implemented automatic logging using Odoo's mail.thread inheritance.

python
class QualityCheckMultiProcess(models.Model):
    _inherit = ['quality.check', 'mail.thread', 'mail.activity.mixin']

    manufacturing_process = fields.Selection(tracking=True)
    material_lot = fields.Char(tracking=True)
    customer_spec_id = fields.Char(tracking=True)
    equipment_id = fields.Many2one('manufacturing.equipment', tracking=True)
    process_temperature = fields.Float(tracking=True)
    process_pressure = fields.Float(tracking=True)
    analyst_signature = fields.Many2one('res.users', tracking=True)
    supervisor_signature = fields.Many2one('res.users', tracking=True)
```

Adding tracking=True to fields automatically logs all changes. The mail.thread inheritance provides a complete audit trail visible in the chatter widget. Every modification is timestamped and attributed to a specific user.

Testing and Validation

We created test batches to validate the module. The first test revealed a critical issue: users could bypass signature requirements by directly editing database records. We added server-side validation to prevent this.

We also discovered that the audit trail didn't capture field deletions properly. We modified the tracking mechanism to log null values explicitly. After five rounds of testing, the module met all IATF 16949 requirements.