LEAN MANUFACTURING

 

SUBMITTED BY:- ANURAG BHARTI 2014CC15

PRESENTATION ON

CONTENTS

1.HISTORY2.INTRODUCTION AND DEFINITION3.FOUR PRINCIPLE 4. 7 FORM OF WASTE5.THE 3M’S OF LEAN 6. THE 5S OF LEAN7. LAYING OUT LEAN PRODUCTION FACILITY8. SETUP REDUCTION9. CONTROL OF LEAN PRODUCTION FACILITY10 BALANCING AND TIMING PRODUCTION11. FIVE STEPS OF LEAN IMPLEMENTATION12. REFERENCES

1. HISTORY• The person given credit for initiating this method was Toyota Chief

Engineer named Taiichi Ohno(1912-1990)• He visited American auto industry to learn their production. Due to

various constraint that there company have, These conditions. as well as Ohno's apparent aversion to waste in any form motivated him to develop some of the basic ideas and procedures that have come be known as lean production.

• The term ‘lean manufacturing or lean production was not coined by Ohno’s ,but this word was coined around 1989 with popularity of book “The machine that changed the world” written by researcher of MIT.

• Although lean manufacturing is a relatively new term, many of the tools used in lean can be traced back to Fredrick Taylor and the Gilbreaths at the turn of the 20th century.

2.INTRODUCTION AND DEFINITION

• Lean-: The authors of The Machine that Changed the World. Womack and Jones define lean as doing "more and more with less and less-less human effort, less equipment, less time, and less space-while coming closer and closer to providing customers with exactly what they want“.

• Lean production-: Lean production can he defined as an adaptation of mass production in which workers and work cells are made more flexible and efficient by adopting methods that reduce waste in all forms.

• Lean Manufacturing-: An operational system that maximizes Value Added, reduces Essential Support and eliminates Waste in all processes throughout the Value Stream.

3. Four principle

The four principle of lean production are-:1. Minimize Waste2. Perfect first time quality3. Flexible production line4. Continuous improvement( Kaizen).

4. 7 FORM OF WASTE

All four principles of lean production are derived from the first principle:minimize waste.. Generally, muda (or waste) can be grouped into the seven types-:1. production of defective parts.2. production of more than till number of items needed.3. unnecessary inventories.4. unnecessary processing steps.5. unnecessary movementof people.6. unnecessary transport of materials.7. workers waiting.Later an eighth waste was defined by Womack et al. (2003); it was described as manufacturing goods or services that do not meet customer demand or specifications

4. 7 FORM OF WASTE (CONTINUE……).

Fig:- 7 form of waste wheel

4. 7 FORM OF WASTE (CONTINUE……) • As waste is eliminated quality improves while production time and

cost are reduced. A non exhaustive list of such tools would include: a. Rank Order Clustering ,b. Value Stream Mapping,c. control charts,d. Five S,e. Kanbanf. poka-yoke (error-proofing) g. Quick Changeover h. Standardized Work etc.

5.THE 3M’S OF LEAN These Ms are: 1. muda, the Japanese word for waste,2. mura, the Japanese word for inconsistency and3. muri, the Japanese word for unreasonableness.5.1 Muda:- As explained it is japanese word for waste and breifly explained above.5.2 Mura:- The second “M” is for mura, or inconsistency. Inconsistency is a problem that increases the variability of manufacturing. Mura is evidenced in all manufacturing activities ranging from processing to material handling to engineering to management. Related figure given below:-

5.THE 3M’S OF LEAN (continue….)5.3 Muri:- The final “M” is for muri or unreasonableness. Muri applies to a variety of manufacturing and management activities . For instance, example of being unreasonable by blaming someone for problems rather than looking at resolution of problems. It is unreasonable to blame rather than mitigate issues. This is true for all manufacturing activities -- do what is reasonable.

6. THE 5S OF LEAN

• The 5 S’s are from Japanesse and are:• Seiri (sort, necessary items)• Seiton (set-in-order, efficient placement)• Seison (sweep, cleanliness)• Seiketsu (standardize, cont. improvement)• Shitsuke (sustain, discipline)

6. THE 5S OF LEAN (continue………..)

Fig: 2 These concepts are illustrated below

7. LAYING OUT LEAN PRODUCTION FACILITY

• Another critical aspect of Lean is the organization of the production facility. the layout of any system should be arranged in such manners that waste of motion (material handling and material transport) and elimination of inventory is part of the object for the layout.

• Two traditional forms of layout in manufacturing are:-a. Process layout (or job shop as it is informally called),b. Product layout (or flow shop).

7. LAYING OUT LEAN PRODUCTION FACILITY (continue………..)

Process systems work effectively on “one of a kind” type of production. As batches get larger, these systems fail to produce the required “economies of scale”, and that production time and cost remains relatively constant. In general, very low volume items should be produced on process type systems

A typical product or flow shop layout

7. LAYING OUT LEAN PRODUCTION FACILITY (continue………..)• Product layout systems are used effectively for the economic

production of high volume goods. As, machines are located so that sequential operations are performed at adjacent machines.

• In general, very low volume items should be produced on process type systems, and very high volume items should be produced on product type systems. A problem facing most manufacturers is that the general trend today is for medium volume batches that change regularly. This means that process and product layout fails to meet the requirements for much of what is demanded today. The result is that a hybrid of the two systems has been developed. It is called a manufacturing cell.

• Cells are used to make families of parts, rather than just one-of-a-kinds or high volume items. Cells are logical clusters of machines organized to produce a variety of parts requiring the same equipment type, tooling and fixtures

7. LAYING OUT LEAN PRODUCTION FACILITY (continue………..)

cellular layout separates and groups products within a manufacturing system into smaller units. The strategy here is to identify parts that belong to the same “product families”. A product family is a group of products that normally look similar and require the same (or similar) processing steps to produce. The problem however becomes one where functional names may create very large families . Problem was however solved when Group technology (GT) was introduced as a method to characterize products into code-able families.

Typical Manufacturing Cell layout

8. SETUP REDUCTION

• One of the methods employed in cutting fat from a lean production system is to reduce the time required to setup production equipment.

• The best know method is SMED (Single Minute Die Exchange of die).

• It received its name because when used effectively, setup times of a day or more for manufacturing presses can be lowered to minutes.

• SMED is a process that begins with detailing what happens to a machine between batches of parts.

• In order to begin setup reduction activities, the first step of the process is to document all of the requirements and specifics for adjacent lots or parts.

• Once the documentation is done, each setup element is classified into two:-

1. Internal element2. External element

8. SETUP REDUCTION (continue……)• Once setup is documented, each setup element is analyzed in

order to determine if the element is an internal or external element.

• An internal element is one that requires the equipment resource. An external element is one that can be done without the equipment or external to the equipment.

• For example, in NC machine qualifying the tooling with respect to the part or fixture would be an internal element and Loading the tools into tool holders would be an external element.\

• The key here is to keep critical resources operating as long as possible. In order to accomplish this, external elements should be conducted in parallel with machining.

8. SETUP REDUCTION (continue……)

•

• Fig: Running a machine while external elements are complete.

8. SETUP REDUCTION (continue……)

• Fig: Saving time using external element reduction • Using internal and external elements is one part of setup

reduction. In addition to using external elements in parallel, applying good methods engineering practice is also critical to reduce setup time.

9. CONTROL OF LEAN PRODUCTION FACILITY

• As we know,largest portion of time a part spends in a manufacturing facility is spent waiting rather than having value added. The result is that Lean Manufacturing has become more than just eliminating waste.

• several production control techniques that have been used as part of lean developments.

• In traditional factory control, “push” control was the strategy used to regulate parts in a production environment. That is, when an operation was complete at a machine, the product or part was pushed to the next machine. Many of the Materials Requirements Planning (MRP) software systems use this type of strategy.

• many flow systems use “Pull” control rather than “push”. In this, parts or product is held at a manufacturing station until approval is issued from a downstream machine.

9. CONTROL OF LEAN PRODUCTION FACILITY (continue…………..)• Also referred to as a kanban system. Kanban is Japanesse word that

refers to the “paper authorization or approval” to continue to move a part.

• Kanbans typically come in two varieties – production and transport .

• Fig: Showing way the pull and Push System Operates.

10 BALANCING AND TIMING PRODUCTION• Pull-based production control systems tend to balance activities. These

systems however only work on flow systems so it is important that part families are created so that the product in a manufacturing facility moves in a common direction. When the control of these systems is implemented correctly, these systems are called Just-in time (JIT) manufacturing systems, because the product arrives as it is needed. This helps to reduce the inventory and highlight trouble spots in manufacturing.

• Wild variations in product mix and production times this systems may perform even worse than traditional systems because little or no buffer is available

Kanban and JIT are also based on several other system requirements. These are: 1 Stability of preceding process 2 Leveled production 3 Takt time and production requirement 4 Maintaining good quality 5 Team member education and training

10 BALANCING AND TIMING PRODUCTION (continue……)10.1 Word about JIT“In the broad sense, an approach to achieving excellence in a manufacturing company based upon the continuing elimination of waste (waste being considered as those things which do not add value to the product). In the narrow sense, JIT refers to the movement of material at the necessary time. The implication is that each operation is closely synchronised with subsequent ones to make that possible”PRE JIT Traditional Mass Production Big lot sizes

Lots of inventory”PUSH” material to nextstage

Lowerper unit

cost

Big purchase shipments

Big “pushes” of finished goodsto warehouses or customers

???

Fig :- Showing work going on in a PRE JIT Traditional Mass Production

10 BALANCING AND TIMING PRODUCTION (continue……)

• Post-JIT: “Lean Production” • Tighter coordination along the supply chain  ,Goods are pulled along only make and ship what is needed

• Fig :- Showing work going on in a Post-JIT: “Lean Production”

Smaller lotsFaster setupsLess inventory, storage space”PULL” material to next stage

Minimalor no

inventoryholding

cost

Smaller shipments

Goods are pulled out ofplant by customer demand

11. FIVE STEPS OF LEAN IMPLEMENTATION

• The process used to implement lean manufacturing is a straightforward one.

• The steps associated in implementing lean follow: Step 1: Specify Value Step 2: Map Step 3: Flow Step 4: Pull Step 5: Perfection

11. REFERENCES

1. Automation, Production Systems, and Computer-Aided Manufacturing , Mikell P. Groover, Prentice Hall, 1992.

2. Lean Maintenance, By Ricky Smith, Bruce Hawkins, Elsevier , Butterworth-Heinemann ,2004.

3. http://en.wikipedia.org/wiki/Single-Minute_Exchange_of_Die4. http://en.wikipedia.org/wiki/Lean_manufacturing5. Introduction to Operations and Supply Chain Management, 2/e --- Bozarth and Handfield, 2008 Pearson Prentice Hall --- ISBN: 0131791036

THANK YOU