In a pull system all the processes are dependent on customer demand. All the processes are coordinated so as the get finished product right on time as per customer’s requirement.
An example of pull system is “Just in Time (JIT)” which is widely used by Japanese companies. Here the raw materials are brought into the system just at the right time as per the order. Ideally in this system inventory would be close to zero as all the products are manufactured only after the order.
Dell uses pull system to determine various requirements of the customers through its online ordering and producing as per the requirement only.