Most ERP systems today make use of an RDBMS database (few of them don't) and these systems are capable of handling transactional information (For example inventory maintenance transactions, Material requisitions and processing, Financial - AP / A/R, journals and Sales orders as well as purchase orders). I'm also aware of many businesses who prefer to utilize information from the ERP system to process them through BI tools like Business Objects, QlikView and probably many others. These systems require a database that can store transactional information created on the go and on a real time basis. This becomes importantly mainly because most of the sales orders house sales margin information and inventory tracking (maintaining minimum / reserve stocks) and these have to be updated in many businesses on a real-time basis. Blockchain technology certainly hasn't reached this level of information processing capabilities on a real-time basis. Even with a private blockchain technology like Hyperledger there's' usually information that needs to go into a block which has to be validated and added into the block after one has been made (there's no mining in such case).

Blockchain technology would be useful alongside ERP systems to add "Trust" and to validate inventory movements and adjustments, stock status and very useful for inventory counting. This proves helpful for supply chain management as well to ensure that goods have been delivered by suppliers in right quantties and at the right time without having to worry about middle-men to verify this information and who could possibly maniupalte it.