What are the reasons for keeping stock?

To avoid materials shortage.

There could be five basic reasons for keeping stock:

1) time2) uncertainty3) seasonal demand4) appreciation in value5) economies of scale

In order to avoid any disruption in running operations 

• Five basic benefits are achieved through warehousing:

  • spot stock,

  •  assortment,

  • mixing,

  • production support,

  •   market presence

Best Reagrds.

I agree with the answers been added by EXPERTS. Thanks

1. Time - The time lags present in the supply chain, from supplier to user at every stage, requires that you maintain certain amounts of inventory to use in this "lead time."
2. Uncertainty - Inventories are maintained as buffers to meet uncertainties in demand, supply and movements of goods.
3. Economies of scale - Ideal condition of "one unit at a time at a place where a user needs it, when he needs it" principle tends to incur lots of costs in terms of logistics. So bulk buying, movement and storing brings in economies of scale, thus inventory.

AGREED BY HELMI AND ABDOU......................................