Validating some operations is a common need across different areas in a company
and sometimes it also involves several people and stages in the process. With
this module you will be able to define your custom validation workflows for
any Odoo document.

This module does not provide a functionality by itself but an abstract model
to implement a validation process based on tiers on other models (e.g.
purchase orders, sales orders, budgets, expenses...).

**Note:** To be able to use this module in a new model you will need some
development.

See `purchase_tier_validation <https://github.com/OCA/purchase-workflow>`_ as an example of implementation.