All about Lean manufacturing and its simple tools

Lean manufacturing start with lean, so first we need to understand what is lean. Here Lean is the term that refers to a set of principles and practices to improve efficiency and values by eliminating wastes. Lean starts with the self; here are some examples to understand lean in daily life:

• Well maintained body, regular exercise and walking
• Regular inspection of your body
• Preventive check ups and care to keep overall cost low
• Reduce food after 35, get glasses after 42
• Per minute cost of any process

With above examples we understand lean is about regularly being used practice, consistent practice and self-improved practice for better results.

Overview of Lean Manufacturing: – A way to eliminate waste and improve efficiency in manufacturing set-up. It focuses on flow, the value stream and eliminating muda (waste). In lean manufacturing production is done using less of everything (Design, huma effort, manufacturing space, investment in tools, inventory and engineering time to develop new products.

Lean manufacturing father is Henry ford, although his descendants never practiced it. Later Lean become synonymous  with Toyota Production system (TPS) because Toyota motor company’s Taiichui Ohno and Dr. Shigeo Shingo tools its concept to great heights with lot of innovations.

Background of Lean Manufacturing

Concept of lean develop from Toyota. Sakichi Toyoda make manual looms that were cheap and better quality. Later developed power driven loom, having special mechanism to automatically stop a loom whenever a thread broke. This is building in quality as you manufacture, its called Jidoka (In station quality). Its is known as mistake proof loom. Soon after this mistake –proof become popular.

In 1929 his son Kichiro Toyoda sale the patent right to platt brothers of England for 100,00 euros. With this fund they build Toyota motor corp. Kichiro Toyoda main contribution was for JIT (Just is time) philosophy. After WW2, Toyota motor passed through financial crisis, led to resignation of Kichiro Toyota. Then after this Eiji Toyoda took charge as president of Toyota Motor Corp. His contribution was for development of TPS (Toyota production system). He want to improve company manufacturing process same as ford motors and want to increase production equal to ford. For this he hired Taiichi Ohno as plant manager.

Ohno san closely observed American company manufacturing system and took various idea like- Eliminating waste, reducing inventory, Pull system- Kanban system, external and internal customers, PDCA cycle and Kaizen for improvements. By the time these idea & tools were implemented by Toyota to improve quality and productivity. In lean manufacturing focus is kept on improving efficiency and effectiveness by eliminating waste. To gain wealth and popularity we must take care of every moment & every grain of material.

Pillars of Lean Manufacturing

There are around 11 pillars of lean manufacturing, list of 11 pillar is below (Here lean not cover 11 tools as fixed, there could be more as there is no boundaries for lean.

• 5S
• Visual Management
• 8 Wastes
• Poka Yoke
• JIT
• Jidoka
• SMED
• VSM
• TPM
• OEE
• Single piece flow

Let’s understand each pillar in detail:

5S in lean Manufacturing

• SEIRI (Segregation)– Classified clearly the item into necessary and unnecessary categories, then dispose of unnecessary items.
• SEITON (Systematic arrangement) – Place necessary items at proper position for practical usage and clearly indicate the contents so that everyone can understand.
• SEISOU (Cleaning) – Keep cleaning up the working area, floor, equipment, jig, tools and make them always clean.
• SEIKETSU (Standardization +visual control) – Keep 3S in good Condition, keep recording of 3S in daily check sheet.
• SHITSUKE (Discipline/Sustain) – Acquire the habit of doing what has been determined according to the set of rules. Keep all rule such as rule of safety, rule of quality. Here maintain established procedures).

Visual Control in Lean manufacturing

Visual control is recognizing and resolving problems as they occurs. Most of business process adopt visual control for shop floor improvement.

• Visual control should be self-explaining so anyone can understand the current situation
• It should be self-regulatory so everyone can understand you ahead, behind and on track.
• It should be self-improving so everyone can take action where there is an abnormality.
• It should present necessary information to everyone who needs it. Visual controls show what actually is against what should be

Example of Visual Controls

• Operating range display on pressure bar.
• Painted line around box of inventory.
• Andon Lights for immediate response.
• Display board for guiding gangway on shop floor.
• Work instruction with pictures on assembly line.

8 wastes in Lean Manufacturing

Muda, Mura and Muri– are 3 Japanese words talks about wastes in industries. Muda (Waste) is anything that happen to product that does not add value from customer perspective. Type 1 Muda– Necessary waste can be minimized but cannot be eliminated. Ex- Security guard in factory. Type 2 Muda– Can be minimized and eliminated too. Ex- Defect/Transport/Motion/over.

Mura– Mean Irregularity / Inconsistency. Whenever a smooth flow of work is interrupted by an operator’s uneven work, flow of part and machine, then Mura is there. It can occur in Production/Part flow/Equipment/Operator work/Information flow/Material delivery causing shortage or overstock.

Muri– Inconvenience, it means Strenuous condition of both worker & m/c.  Ex- A profusely sweating operator, squeaking sound from m/c, new operator assigns to do experience work without training, uncomfortable posture.

In above picture 8 wastes are- Overproduction, Inventory, waiting, Motion, Transportation, Defect/rework, Overprocessing, Non utilization of talent.

Poka Yoke in Lean Manufacturing

Poka Yoke (Japanese word) is used to avoid inadvertent Errors. It makes mistake proof the process. Mistake proofing recognizes that every human will make mistakes and tries to set up systems that minimize or eliminates those mistakes.

3 rules of Poka Yoke in Manufacturing: 1) Don’t accept defect, 2) Don’t make defect, 3) Don’t pass a defect

JIT (Just In Time) in Lean Manufacturing

JIT minimizes waste, reduces storage costs, and frees up working capital. Just-in-Time (JIT) is a way of managing production and inventory where goods are made or obtained only when needed, in the right amount, and at the right place.

Jidoka in Lean Manufacturing

Jidoka (Japanese word) means Autonomation. It is a component of Lean manufacturing in which production machinery can detect defects independently, without human supervision. When a defect is detected, the machine immediately notifies an employee on duty, who will intervene and resolve the defect. With this we are making line operator autonomous, they free to take decision of their own & can stop the line in case defect is generated.

SMED in Lean Manufacturing

SMED- Single minute exchange of Dies, developed by Dr. Shigeo Shingo. It is a system designed to radically reduce the amount of time to perform the changeover or setup. The goal of SMED is to reduce setup time to less than 10 Minutes. It reduces Downtime (Waste), thus improve OEE.

Changeover -The amount of time taken to change a piece of equipment from producing last good piece of production lot to the first good piece of next production lot.

VSM in Lean Manufacturing

VSM- stand for Value stream Mapping. It is pictorial tool for end-to-end process mapping, showing material and information flow.  It shows every step involve in delivering a product/service.

VSM defines value from the customer’s perspective (Customer will pay only for value added items). In this lean tool we first check current state VSM (Full view of present process) and then we move to future state VSM (How the process should be after improvement)

TPM in Lean Manufacturing

TPM stand for Total Productive Maintenance. It is plant improvement methodology which enable continuous and rapid improvement of manufacturing process through use of employee involvement, employee empowerment and close loop measurement of result.

Goals of TPM in Manufacturing:

• Continuous improvement of Equipment and factory through maintenance.
• Effective uses of Equipment.
• Build comprehensive PM plan.
• Promotes and implement PM activities based on autonomous small group activities.

OEE in Lean Manufacturing

OEE stands for Overall equipment efficiency is the “best practice” or way to monitor and improve the efficiency of your manufacturing processes, which includes machines, manufacturing cell and assembly lines.

OEE = Availability × Performance × Quality

Single Piece Flow in Lean Manufacturing

Single piece flow is key concept which involves moving one piece at a time during through each step of production process.

It is opposite to batch production, which produces items in large lots. This method enhances efficiency by eliminating waiting times, reducing inventory, and improving overall quality. It is closely associated with the Just-in-time system, which aim to minimize waste and maximize values in production.

Conclusion: With this post we have focused on pillars of lean manufacturing. Although details explanation does not write in post, major details are added in photos. Lean manufacturing is helpful in manufacturing industries to maximize profits by reducing wastes. You can download this presentation by writing on contact form in www.autoqualitycentre.com

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