Quantitative ordering method needs to check the inventory frequently, and it is not easy to be out of stock. Each order quantity is generally an economic order batch. From the above contents, it is suitable for class A materials, but I think it is best to say that it is suitable for important materials in CVA classification, but the "double pile method" and "three pile method" are suitable for unimportant class C materials; The conventional ordering method may lead to shortage, and the inventory held may not be the best level, so it is suitable for B and C materials.
Many materials, including textbooks, are inconsistent and confusing. The above is just my understanding.