M cellular manufacturing

Engineering Management

MSE507 Lean Manufacturing

Cellular Manufacturing One Piece Flow for Workteams Chapter 1 An Introduction to Cellular Manufacturing

Cellular Manufacturing Overview 

What Is Cellular Manufacturing?

• One-Piece Flow • High-Variety Production

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Understanding Process and Operations • Process • Operations

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Benefits of Cellular Manufacturing • How It Helps Companies • How it Helps You

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Summary

What Is Cellular Manufacturing?  

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A lean manufacturing approach that helps companies build a variety of products with as little waste as possible Equipment and workstations arranged in a sequence that supports smooth material flow through the process, with minimal transport or delay Derived from the word Cell A Manufacturing Cell consists of people and machines or workstations required for performing the process steps For example - if a process for a product requires cutting, followed by drilling and finishing, the cell would include the equipment for performing those steps, arranged in that order Helps companies achieve two important goals of lean: • One-piece flow • High-variety production

One Piece Flow One-piece flow is the state that exists when products move through a manufacturing process one unit at a time, at a rate determined by the needs of the customer  The opposite of one-piece flow is large-lot production 

• Goods produced in large lots build delays into the process • No items can move on to the next process until all items in the lot have been processed • The larger the lot, the longer the items sit and wait between steps

One-piece flow is an ideal state  In daily operation, it is not always possible or desirable to process items just one at a time The important thing is to promote continuous flow of products, with the least amount of delay and waiting 

One-Piece Flow Vs. Large-Lot Production LARGE-LOT PRODUCTION CAN LOWER A COMPANY’S PROFITABILITY

ONE-PIECE FLOW SOLVES THESE PROBLEMS

Makes leadtime between customer’s order and delivery of product longer

Allows to deliver a flow of products to customers with less delay

Requires labor, energy, and space to store and transport products

Reduces resources required for storage and transport

Increases chances of product damage or deterioration

Lowers risk of damage, deterioration, or obsolescence Exposes other problems so they can be addressed

High-Variety Production 

In the early days, a company could produce one type of product • Customers would buy it even if it wasn’t exactly what they liked

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Today customers expect variety and customization • Specific quantities delivered at a specific time

If your company is not flexible enough to serve their needs customers will go to your competitor  Cellular manufacturing offers flexibility to give customers the variety they want 

• By grouping similar products into families that can be processed on same equipment in the same sequence • Encourages companies to shorten changeover time between products • Eliminates a major reason for large-lot production

Understanding Processes and Operations Converting a factory to cellular manufacturing means eliminating waste from processes as well as from operations  How do Processes and Operations differ and intersect? 

PROCESSES A process is a continuous flow through which raw materials are converted into finished products in a series of operations.  The focus is the path of the materials as they are transformed into something to sell.  Manufacturing processes have four basic types of steps or phases: 

•Transformation – assembly, machining •Inspection – comparison to standard •Transport – change of location •Storage – waiting period

Only Transformation adds value!

OPERATIONS In contrast to process, which focuses on flow, an operation focuses on action.  An operation is any action performed by workers or machines on the materials.  Operational improvements focus on how specific actions are carried out, and include studying the motions required for a specific action. 

Understanding Processes and Operations   

To improve production for lean manufacturing, it is not enough to improve operations Companies must also improve their processes Improving a process involves streamlining the flow of materials to minimize obstacles and wastes such as: 1. Time spent in non-value-adding steps  Such as waiting and transport

2. Downtime caused by changeover and adjustments 3. Distance materials or WIP must travel between transformation steps 4. The need for inspection or rework

The cellular manufacturing approach works on improving the process as well as specific operations

Benefits of Cellular Manufacturing Promoting one-piece flow through cellular manufacturing can help make your company more competitive  Cut costly transport and delay from the manufacturing process  Shortens the production leadtime 

• Serves customer needs • Gives an earlier return on the investment in the product 

Saves space in the factory • Can be used for other value-adding purposes

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Promotes continuous improvement • By forcing solutions to problems that block low-inventory production

How Cellular Manufacturing Helps You? Cellular manufacturing also helps you as a company employee  By straightening the company’s competitiveness, it helps support job security  Makes daily production work go smoother by: 

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Removing clutter of excess WIP inventory Reducing transport and unnecessary handling Reducing walking required to complete processes Addressing causes of defects and machine problems that cause delays

You may have to learn a process sequence you have not done before.

• Raise your skill and flexibility, and may change how you think about your role in the company

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Learning about and participating in a JIT transformation ultimately will make you more employable!

Summary 

Cellular Manufacturing • Lean manufacturing approach that helps build a variety of products with minimum waste

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Equipment and workstations arranged in a sequence with a smooth flow of materials and components through the process • Minimal transport or delays

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One-piece flow • Products move through a manufacturing process one unit at a time, at a rate determined by the customer’s needs

Cellular Manufacturing gives the flexibility to give customers the variety they want  Converting a factory to cellular manufacturing means eliminating waste from processes and from operations 

Engineering Management

MSE507 Lean Manufacturing

Cellular Manufacturing One Piece Flow for Workteams Chapter 2 Working in a Manufacturing Cell

Chapter 2 Overview 

Operating in a U-Shaped Cell

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Becoming Multi-skilled, Multi-machine Operators • Cross-Training for Maximum Flexibility • Moving with the Work

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Using Small, Flexible Machines

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Using Autonomation (Jidoka) to Eliminate Machine Watching

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Summary

Operating in a U-Shaped Cell Changing from an operation-based layout to manufacturing cells will change how people do their work in the factory  In a manufacturing cell, the equipment and workstations are arranged close together in sequence of processing steps 

• Reduce unnecessary walking and transport to promote flow 

The equipment in a cell is usually laid out in a curved shape • The operator’s path is like a U or C

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These shapes bring the end point of the process close to the beginning point • Minimizes distance the operator has to travel to begin the next cycle

Becoming Multiskilled/Multimachine Operators Creating a manufacturing cell often changes the relationship between people and and machines in the workplace  Operators may need to learn how to run different types of equipment to support the process  In cells where automatic machines are used, most of the operator’s time is spent watching the equipment run 

• Such waste is avoided by teaching people to operate several different machines in the process • Operators can be setting up a workpiece for step 2 while step 1 machine is processing another workpiece 

A cell may be run by one person or by several people working together • Depending on the size of the cell, cycle times, or production volume

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Flexibility to change how people work together in a cell comes from cross-training

Cross-Training for Maximum Flexibility 

Cross-training enables employees to perform different functions within a process • Lets teams take full responsibility for their processes.

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Operator trained on several machines is qualified to respond to changes in production needs by performing different tasks as needed • This versatility makes employees more valuable to their teams and to their companies

Cross-training is a source of employee pride in many workplaces  Visual display charts are often used to recognize people’s skill attainment in a public way 

• Cross-training metrics

Moving with The Work 

Running several machines in sequence • An operator needs to work standing up rather than sitting down

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To assist one-piece flow manufacturing • People stand and walk so that work moves smoothly through the process

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Working while standing • Enables people to respond more quickly if machine problems occur

Using Small, Flexible Machines 

A cellular manufacturing process may use equipment different from that used in large-lot production • Works best with machines that are smaller and often slower than large-lot equipment

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Smaller machines save space • Placing them close together reduces walking distance • Leaves no space for excess WIP to accumulate

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Slower machines are appropriate • They can produce one piece at a time at a speed determined by customer requirements

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Machines for cellular manufacturing • Flexible and be easy to set up quickly • Used to make a greater variety of products during a single shift

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Smaller machines are less expensive • Easier to operate and maintain

Using Autonomation (Jidoka) to Eliminate Machine Watching Autonomation - an approach to automation that gives equipment “intelligence” so people don’t have to monitor automatic operation  “Autonomated” machines - semi-automatic machines that autonomously (independently) support one-piece flow processing: 

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Stop and signal when a cycle is complete or when problems occur Often loaded by operators Often set up to unload automatically after processing Do not have to be tended

Many companies invest in automation • People don’t have to perform difficult, dangerous, or repetitive work

Summary Equipment and workstations arranged close together in sequence of processing steps (U or C)  Relationship between people and machines changes 

• Operators may need to learn how to run different types of equipment to support the process 

Machine-watching is avoided • Teaching people to operate several different machines

Flexibility to change how people work together in a cell comes from cross-training  Cellular manufacturing works best with smaller and often slower machines  Autonomation (jidoka) is an approach to automation that gives equipment “intelligence” so people don’t have to monitor automatic operation 

Homework Assignment What did you learn from chapter 1 that stands out as particularly useful or interesting?

2. What did you learn from chapter 2 that stands out as particularly useful or interesting?

1.

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Read Cellular Manufacturing •

Chapters 3 & 4 (pages 22-61)

Questions? Comments?