Odoo studio
Odoo studio is a feature which allows Odoo users to do changes in the system without changes of source code itself so small amount of money can be saved when changes are not made in code. It sounds like a good feature, but it´s recommended to use it only in cases where following conditions are met:
Small changes are done (adding fields, reports)
Perfect change log and documentation is made for each change done in Odoo studio
No other customizations are planned in the future (changes in source code is complicated after using of Odoo studio)

So it can cause a lot of problems with future code development where the programmers can´t see these changes and many errors and strange behavior of the system can app.
Changes are saved only to database (not visible in the source code)
It can be difficult to do programmer modifications of Odoo parts already changed in Odoo studio
It can cause much higher cost price of code customizations in the end
Unqualified usage of Odoo studio can cause errors and slowing the system
Code customizations are recommended in all other case.
We can help you with customization of your Odoo.