Just-in-Time Manufacturing

A. INTRODUCTIONA. INTRODUCTION

Why “Just-in-Time” manufacturing ?Why “Just-in-Time” manufacturing ? No large capital outlays required.No large capital outlays required.

Advocates simplifying and streamlining existing process.Advocates simplifying and streamlining existing process.

Planning is entrusted to shop floor personnel.Planning is entrusted to shop floor personnel.

No-cost, or low-cost method for improving mfg. process.No-cost, or low-cost method for improving mfg. process.

B. JIT PHILOSOPHYB. JIT PHILOSOPHY

Basis is the concept of ideal production.Basis is the concept of ideal production. Centers on the elimination of waste- from raw material to Centers on the elimination of waste- from raw material to

shipping.shipping.

Defined as: “Production of the minimum number of units Defined as: “Production of the minimum number of units in the smallest possible quantities at the latest possible in the smallest possible quantities at the latest possible time, which eliminates the need for inventory”.time, which eliminates the need for inventory”.

Does not mean to produce on time but to produce “just in Does not mean to produce on time but to produce “just in time”.time”.

B. JIT PHILOSOPHYB. JIT PHILOSOPHY

1. History of Just-in-Time1. History of Just-in-Time• Incorrectly rumored to have been invented by Henry Ford.Incorrectly rumored to have been invented by Henry Ford.

• Actually invented by Taiichi Ohno of Toyota.Actually invented by Taiichi Ohno of Toyota.

• Ohno’s system designed to handle varying Ohno’s system designed to handle varying volumes/various parts.volumes/various parts.

• Nothing more than good, common sense manufacturing.Nothing more than good, common sense manufacturing.

B. JIT PHILOSOPHYB. JIT PHILOSOPHY

2. From Supermarket to Shop Floor2. From Supermarket to Shop Floor• Ohno is believed to have gotten his JIT idea from U.S. Ohno is believed to have gotten his JIT idea from U.S. supermarkets.supermarkets. Customers pull items from shelf.Customers pull items from shelf.

Empty space on shelf is signal for stocker to replace item.Empty space on shelf is signal for stocker to replace item.

If items are not bought, no replacement required.If items are not bought, no replacement required.

When item become low, stocker reorders from supplier.When item become low, stocker reorders from supplier. Customers take only what they need because they know items willCustomers take only what they need because they know items will be restocked.be restocked.

• Ohno applied the same concept to manufacturing.Ohno applied the same concept to manufacturing.

B. JIT PHILOSOPHYB. JIT PHILOSOPHY

3. What to Expect3. What to Expect• JIT is more than an inventory system.JIT is more than an inventory system.• It is an operational philosophy which includes:It is an operational philosophy which includes: A set-up time improvement system.A set-up time improvement system.

A maintenance improvement system.A maintenance improvement system.

A quality improvement system.A quality improvement system.

A productivity improvement system.A productivity improvement system.

• A properly implemented JIT system should:A properly implemented JIT system should: Produce products customers want.Produce products customers want.

Produce products only at the rate customers want them.Produce products only at the rate customers want them.

Produce with perfect quality.Produce with perfect quality.

Produce instantly with zero unnecessary lead time.Produce instantly with zero unnecessary lead time.

Produce with no waste of labor, material or equipment.Produce with no waste of labor, material or equipment.

B. JIT PHILOSOPHYB. JIT PHILOSOPHY

3.3. What to ExpectWhat to Expect• Elements of the implementation process Elements of the implementation process

include:include: Reductions in set-up time;Reductions in set-up time;

A formal preventive maintenance program;A formal preventive maintenance program;

Utilization of quality circles;Utilization of quality circles;

Cellular manufacturing techniques;Cellular manufacturing techniques;

Cross training of employees;Cross training of employees;

Quality certification of suppliers;Quality certification of suppliers;

Reductions in vendor lead time;Reductions in vendor lead time;

Reductions in lot sizes;Reductions in lot sizes;

Sole sourcing, andSole sourcing, and

Presence of one who “championed” the cause in the company.Presence of one who “championed” the cause in the company.

B. JIT PHILOSOPHYB. JIT PHILOSOPHY

3.3. What to ExpectWhat to Expect• Benefits of JIT implementation include:Benefits of JIT implementation include: Reductions in downtime;Reductions in downtime;

Reductions in inventory;Reductions in inventory;

Reductions in scrap and rework;Reductions in scrap and rework;

Reductions in work space;Reductions in work space;

Increased inventory turns;Increased inventory turns;

Increased labor utilization;Increased labor utilization;

Increased equipment utilization; andIncreased equipment utilization; and

Improved service to customers.Improved service to customers.

C. FIRST IN – FIRST OUT C. FIRST IN – FIRST OUT (FIFO)(FIFO)

• A method of inventory rotation to ensure that A method of inventory rotation to ensure that oldest inventory (first in) is used first (first oldest inventory (first in) is used first (first out):out):

Simply means how you handle your products;Simply means how you handle your products;

• For example, groceriesFor example, groceries Perishable items (milk and eggs) restocked from the back;Perishable items (milk and eggs) restocked from the back;

Old items are pushed to the front;Old items are pushed to the front;

Selected first by the customer.Selected first by the customer.

FIFO Racks

D. TAKT TIMED. TAKT TIME

• ““TAKT” – German word for baton an TAKT” – German word for baton an orchestra conductor uses to regulate the orchestra conductor uses to regulate the speed, beat or timing at which musicians speed, beat or timing at which musicians play.play.

The rate or time a completed product is finished.The rate or time a completed product is finished. 2 minutes, 2 hours, 2 days, or 2 weeks.2 minutes, 2 hours, 2 days, or 2 weeks.

1.1. How is Takt Time Established ?How is Takt Time Established ? Established by customer buying rate.Established by customer buying rate.

2.2. What if Customers Buy Fewer Products?What if Customers Buy Fewer Products? Takt time changes to adjust to customer buying rate.Takt time changes to adjust to customer buying rate.

Increases or decreases result in staffing and Increases or decreases result in staffing and production changes.production changes.

3.3. What if Customers Buy More Products?What if Customers Buy More Products? Takt time decreases to make more products in shorter Takt time decreases to make more products in shorter

time.time.There is no substitute for continuously improving a balanced Takt time.