Presentation Kanban

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JIT and Lean Operations

KANBAN IMPLEMENTATION AT A TYRE MANUFACTURING PLANT Venkatesh KBS

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JIT and Lean Operations

JIT/LEAN PRODUTION • Just-in-time

(JIT): A highly coordinated

processing system in which goods move through the system, and services are performed, just as they are needed, • JIT

  lean production

• JIT

 pull (demand) system

• JIT

operates with very little “fat”

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JIT and Lean Operations

KANBAN •

The heart of the JIT system is the Kanban

•

Kanban: Card or other device that communicates demand for work or materials from the preceding station

•

Kanban is the Japanese word meaning “signal” or “visible record”

•

Paperless production control system

•

Authority to pull, or produce comes from a downstream process.

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JIT and Lean Operations

Uses of Kanban system Reducing inventory Eliminating stock-outs Replacing massive computers Slashing overheads Improving service and product quality

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JIT and Lean Operations

Kanban Misconception It is seen as a pure production method having little or nothing to do with the surrounding environment •

Kanban focuses on the mathematical complexities of Kanban or elaborate abstract rules of operating Kanban with inadequate attention to its practicality and implacability on the shop floor.

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We aim to keep the above misconceptions to rest by developing an easy to implement set of operating rules at a tyre manufacturing plant.

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JIT and Lean Operations

Kanban implementation The Kanban system was implemented at the auto ancillary unit producing tyres for both 1) OEM & 2) Replacement market. Phase Induction

Particulars Model area selection, Training, Design of Kanban and board Implementation 5S, SMED, Multi skilling, SPC and operating rule Pilot run, Evaluation against set values of Evaluation parameters

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JIT and Lean Operations

Master scheme for Kanban implementation MASTER SCHEME for Kanban implementation sep05 1 2 Selection of model area Layout improvement Multifunction workmen training Reduction of setup time by SMED Pilot run

oct05

3 4 1 2

nov05 3 4 1 2

3

dec05

jan06

1

1

2 3

2 3

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JIT and Lean Operations

Induction phase •

Selection of model area: Extrusion process/area where mixed compounds from the previous stage are fed and extruded components are use for tyre building process. WHY- It has excess capacity and enough space to accommodate increased WIP and changeovers.

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JIT and Lean Operations

Induction phase •

Project team formation: 1 industrial engineer, 2 production officers, 1 maintenance engineer, 1 technical officer and operating crew.

•

Introductory education and campaign: Group training & individual training.

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Kick off : Sense of responsibility & recognize the importance of the task

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Implementation phase •

Introduction of 5S in model area { Housekeeping} STEP 1: Zone preparation 1.1 prepare zone map 1.2 Identify team for each zone & sub zone 1.3 Arrange awareness training STEP 2: Kick off STEP 3: Implement 5S in the model area

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•

5S

STEP 3.1:SEIRI ( sorting necessary from unnecessary items) inventory 3.1.1: Identifying red tag targets equipment space

3.1.2: Make and attach red tags 3.1.2: Evaluate and decide the frequency of sorting and responsibility • STEP 3.2: SEITON (Systematic arrangement) 3.2.1: Determine and prepare locations 3.2.2: Indicate item names and make orderliness your habit

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5S STEP3.3: SEISO ( Cleanliness) 3.3.1: Prepare cleanliness inspection check list 3.3.2: conduct cleanliness audits 3.3.2: Evaluate and decide frequency & responsibility of inspection. • STEP3.4: SEIKETSU ( Standardization) 3.4.1: Prepare and conduct 5 point check for first 3S 3.4.2: Decide frequency of evaluation & responsibility •

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5S •

STEP 3.5: SHITSUKE ( Self discipline) 3.5.1: Distribute 5s badges & 5s stickers 3.5.2: Prepare and conduct 5s checklists, 5s photo exhibits STEP 4: Evaluation of 5S implementation STEP 5: Documentation & display 5S results

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Layout improvement & identification system EXTRUDER(PRODUCER)

C O N S U M E R

EMPTY TROLLEY

COMPONENT BOOKER

EXTRUDATE LOADED TROLLEY

I N P U T

OPERATOR

TECHNICAL COLOURED SCRAPED HOLD COMPONENTCOMPONENT

TROLLEY

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Implementation phase •

Multifunctional workmen training: In sync with Kanban, workmen were trained on each other’s job and rotated at different job positions

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Reduction of setup time by SMED

•

Why SMED Looks familiar

To eliminate the wastes that result from “uncontrolled” processes increasing inventories and lead times.. To gain control on equipment, material & inventory. Apply Control Techniques to Eliminate Erosion of Improvements. Standardize Improvements for Maintenance of Critical Set-up Parameters.

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Steps followed for SMED project STEP1: Select m/c as a model m/c STEP2: Form SMED team STEP3: Conduct training and implement SMED in Model m/c STEP3.1: Study the changeover operations STEP3.2: Classify setup operations in internal, external setups and waste STEP3.3: Identify wasteful operations and apply 5S STEP3.4:Convert internal setup into external internal setup STEP 4:Improve internal setup STEP 5:Improve external setup STEP6:Develop SOP and evaluate performance

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Implementation phase •

Small lot size run & production smoothing : One card Kanban system was selected because of its simplicity in operation and monitoring. Buffer was held at supplying workstation due to following reasons: Number of consuming workstations:17 producers:1 Less transport lead time from producing workstation Shortage of space at consuming workstation. Transport mechanism used was leaf trolleys Ease of monitoring and control.

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IMPLEMENTATION PHASE Buffer sizing (number of kanban in the system): The buffers were designed to accommodate shown constraints and variables while working on them. Factors considered for calculation of number of Kanban • Breakdowns • Preventive maintenance • Absenteeism • Quality problems • Product mix & container transport time •

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Implementation phase Number of kanbans has been calculated as follows: • Number of Kanbans: demand rate*(manufacturing lead time+safety time) container (leaf trolley) size Demand rate is the requirement per day for the next stage process Manufacturing time = setup time+processing time+aging time+movetime+container fill time Safety time is 10% of manufacturing lead time •

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Implementation phase •

Signaling mechanism: Kanban card used

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Priority control using kanban board KANBAN

BOARD

Tread A

B

C

D

E

F

sidewall rim strip G

H

I

J

A

B

C

D

E

F

G

H

Kanban box

I

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Implementation phase 3 zones –critical, moderate and safe • Beginning of each of the schedule, operator will scan the board left to right in the red zone and pick up the size having minimum number of card and schedule the size on the machine. • Similar procedure will be adopted for yellow and green zone. • Day to day scheduling will be done using the extruder board. • Implementation of SPC and visual control •

Use of kanban board by producer &user

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•

Customer: The number of cards withdrawn from the board placed in the box will be equal to the number of trolleys withdrawn from the extruder storage area. Sequence- green-yellow-red

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Supplier: The number of cards placed on the kanban board from the box will be equivalent to the number of loaded trolleys placed in the extruder storage area. Sequence-red-yellow-green

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Kanban work flow Flow of work 2

• •

3

Worker 2 finishes a part, outbound moves over 2 gets another part to work on: • •

2 takes off 1’s green tag giving it back to 1, and puts on her blue tag and moves it into position.

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Kanban Flow of work 2

•

When 3 finishes a part, • • • •

•

3

Finished parts move over one spot He has to have a red tag available to put on, He gets a part from 2’s outbound pile, And gives the blue back to 2

3’s production will be taken by 4, offstage right.

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Kanban 2

3

3 finishes a part, adding it to his out pile

•

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3 Takes part from 2, giving back blue kanban and putting his red one on it.

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Kanban 2

•

Red finishes his part next. 2

• •

3

3

But 4 hasn’t freed up any of the red kanbans, so there is nothing for 3 to work on now. 3 could maintain his machine, or see if 4 needs help

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Evaluation phase •

The system was evaluated after three months of running on pilot basis.

Parameter

present level

After kanban

WIP inventory

3 shift

2.1 shift

% changes and set up time

14%

10%

Time lost due to materials, absenteeism etc

5%

2.5%

Machine scheduling

centralized

decentralized

% rejection

6%

3%

64 min

30min

3281min

4000min

8

10

Equipment reliability No of size change/shift

-MTTR -MTBF

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Conclusion

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A kanban system allows a company to use just in time production and ordering systems, which allow them to minimize their inventories while still satisfying customer demands with improved services and quality.

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THANK YOU