PRESENTED BY SATYAJIT RANJEET CHINMOY

SUROJPUNEET

WHAT IS JIT?

Just-in-time (JIT) is an inventory strategy that strives to improve a business's return on investment by reducing in-process inventory and associated carrying costs.

History Introduced in Japan in 1980.

Western industry calls JUST IN CASE

Type of relationship:

internal JIT

external JIT

OBJECTIVE Produce only the products the customer wants.

Produce products only at the rate that the customer wants them.

Produce with perfect quality

Produce with minimum lead time.

Produce products with only those features the customer wants.

JIT PRINCIPLES

Create flow production • one piece flow.

• machines in order of processes. • small and inexpensive equipment . • U cell layout, counter clockwise. • multi-process handling workers • easy moving/standing operations. • standard operations defined.

CONCEPTS OF JIT

Elimination of waste & variability.

Pull system & Push system.

Manufacturing cycle time.

waste reduction & variability

a)Waste reduction :

waste are any activity that does not add value to products from customer’s perspective.

b)Variability reduction :

Variability is any deviation from the optimum process that delivers perfect product on time, every time.

PULL SYSTEM Produce only when material is needed

downstream.

Pull materials sequentially through the factory.

Orders placed at end item level.

Idle material is waste.

Need discipline,

PUSH SYSTEM

Production authorized in anticipation of needs downstream.

Orders launched to meet due dates.

Keep machines & people busy.

Manufacturing cycle time

It is the time between the arrival of raw materials and the shipping of finished product.

JIT helps in reducing of cycle time.

Characteristics of JIT Systemsa) Pull method of material flow The pull concept is used both within the

immediate production process and with suppliers.

b) Constantly high quality JIT systems control quality as the source, with

workers acting as their own quality inspector.

c) Small lot size Users of jit system maintain inventory with lot

sizes that are as small as possible.

Continued……….d) Uniform work station loads

The JIT system works best if the daily load on individual workstation is relatively uniform.

e) Standardized components and work methods

It helps in achieving the high productivity & low inventory objectives of JIT systems.

f) Flexible workforce

Workers in flexible workforce can be trained to perform more than one job

continued

g) Automated production :

It plays a big role in JIT systems and is a key to low cost production.

h) Preventive maintenance :

Total preventive maintenance concepts makes workers responsible for routinely maintaining their own equipment and to develop employee pride in keeping their machines in top condition.

ELEMENTS OF MANUFACTURING SYSTEM

Eliminating waste.

Enforced problem solving

Continuous improvement

People involvement

Total quality management (TQM).

Parallel processing

MAJOR TOOLS AND TECHNIQUES OF JIT

a) Kanban system or Pull scheduling

b) Set up time reduction.

Kanban system or pull scheduling It’s a physical control system

consisting of cards & containers. The system is used to signal the need for more parts and to ensure that those parts are produced in time to support subsequent assembly.

‘Kanban’ is a Japanese word which means ‘card’ and these cards are the means of communicating within a work centre.

Number of container needed The number of container needed to operate a

work center is given by :

n =DT/C

n=total number of container

D=demand rate of the using work center.

C= container size in number of parts

T=time for a container to complete an entire circuit

Minimizing Waste: Kanban Control System

Work center A

Work center BInput

area Final Assembly Line

Material Flow

Card (signal) Flow

Withdrawal kanban

production kanban

Benefits

Less confusion over sequence of activities. Less obsolescence of inventories while in

storage. Smaller floor space requirements for storing

inventory. Reduced lead times Improved quality Higher employee productivity.

Set up time reduction.

Set up time is the time and cost required for setting up the whole production process.

If set time is long, more products should be produced in one batch to reduce the cost per unit.

Components of set time reduction

Process preparation time.

Process tear down time.

Learning time.

Objectives

Evolve towards lot size of one unit.

Run every part every day.

Make the first piece right every time.

Keep up set times for 10 minutes.

JIT implementation

a) Consistently high quality.

b) Uniform facility loads.

c) Standardized work methods.

d) Flexible work force.

e) Automation.

f) Preventive maintenance,

g) Pull method of materials flows.

h) Line flow strategy.

BENEFITS OF JIT It reduce space requirements.

Reduce inventory investment in purchased parts , raw materials , work-in-process and finished goods.

Reduced manufacturing lead times.

Increase the productivity of direct labour employees, indirect support employees and clerical staff.

Continued

Increase equipment utilization. Reduce paper work. Require only simple planning system. Set valid priorities for production

scheduling. Encourage participation by the work

force. Increase product quality.

Example: TOYOTA AUTOMOBILESa) 30-70% reduction in inventory levels.

b) 40-90% reduction in throughput time.

c) 40-70% reduction in floor-space requirements.

d) 50-90% reduction in cost of quality.

e) 70-90% reduction in change-over times