Hi,

One option is to override the "_src_id_default" function, to get your desired location as default source location.

For that you just need to redefine the field and function in your custom module python file. Just put the following code in your .py file. Replace the search term by your location name. Hope you are working in v8.

class mrp_production(models.Model):
    _inherit = 'mrp.production'
        
    
    def _src_id_default(self):
        
        location_id = self.env['stock.location'].search([('name', '=', 'My Location')])
        if location_id.id:
            return location_id.id
        else:
            return False

    location_src_id = fields.Many2one('stock.location', string = 'Raw Materials Location', required=True,
            readonly=True, states={'draft': [('readonly', False)]},
            help="Location where the system will look for components.", default=_src_id_default)