JIT just in time system depends mainly on one of the following what is it ?

3. decreasing of inventory.

JIT (Just In Time) refers to a purchase system where the inventory is not held by the company in stores and orders it as and when required there by saving significant storage / holding costs.

In majority of cases JIT is considered as part and parcel of Total Quality Management (TQM)

3- Decreasing of inventory as JIT mainly focus on delivering the required production materials in time for production without maintaining additional inventory to minimize/eliminate carrying cost of inventory.

3- decreasing of inventory as finished goods and raw material is reduced to the least level

JIT is mainly concerned about reducing the inventory in hold thereby reducing the holding cost of the inventory and also eliminating obsolete or out of date inventory. 

Example of company which follow JIT is famous British supermarket Tesco. 

Just in time inventory decreases inventory. 

1. decreasing of inventory : To reduce the Holding cost and ordering cost .