Supply chain of a book store comprises four different process cycles, which are:

$1)$ Customer order cycle;

$2)$ Replenishment cycle;

$3)$ Manufacturing cycle; and

$4)$ Procurement cycle.

These cycles, however, are not watertight classifications. Generally each cycle exists between the edges of two succeeding stages of supply chain. Moreover, depending upon the nature of product, the cycles in a supply chain can vary.

In a book store, the push and pull boundary can be located on the basis of whether the order for the book is placed in response to the customer demand or in anticipation of the customer demand.

If the order of the book is placed in response to the customer$$s demand, then it is called pull process. And when the order of the book is in anticipation of the customer$$s demand, then it is called push process.

In the supply chain of a book store, the dividing line between the pull and push process is the customer order cycle and replenishment order cycle. That is$,$ below the customer order cycle, namely, replenishment, manufacturing and procurement order cycles are called push process. This is because changes in these cycles take place in anticipation of the customer$$s demand. Whereas, customer orders cycle is a pull process, because changes in this cycle are in response to the customer demand.