There are some confusions about production signage and accessories supermarket. What should I do?

In the process of promoting lean, the company uses a large number of kanban and auxiliary material supermarket practices. The specific practices of these two methods in a certain workshop are as follows: Kanban: Kanban materials are all purchased raw materials and are set up on the assembly line. beside. There is no confusion about production access, but the problem is that the replenishment of the kanban is not done by the supplier but by its own warehouse. That is to say, after materials are purchased in large quantities (such as purchasing a month's usage), they are first put into the warehouse, and then the warehouse managers allocate the materials to each kanban according to the kanban card and demand according to the kanban settings (such as a week's usage). My question is: What is the role of the Kanban board in this situation? From the analysis of the value stream map, firstly, the inventory has not been reduced, but a part of the inventory has been dispersed by the warehouse to the on-site Kanban; secondly, materials are directly sent to the production line according to the daily production schedule with the warehouse, and there is an additional process of transporting and placing them on the Kanban. Of course, the frequency of feeding the warehouse can be reduced, but these operations are transferred to the picking of the production spider. In my opinion, this kind of signage is more like moving the warehouse to the production line. Accessory material supermarket: It turns out that the accessory materials supermarket contains some small packaging components, and the consumption is large. If the ERP is run according to the BOM to control, the inventory accuracy is very low, and material shortages often occur. There are about 800 such excipients. Now, we plan to transfer hundreds more materials to the excipient supermarket. Some materials are basically not lost during actual use. I think running ERP through BOM can provide better control and management. My question is: What are the standards for transferring materials from BOM to auxiliary materials supermarket? What are the benefits? Please help teachers to clear up the confusion. grateful!