Sounds like they need an ERP. They could try out Odoo https://www.odoo.com/ https://www.odoo.com/ it has an open source version that can be self hosted as wel

Sounds like they need an ERP. They could try out Odoo https://www.odoo.com/ https://www.odoo.com/ it has an open source version that can be self hosted as well as their cloud hosted version with more modules available.