Lean Manufacturing – Cheat Sheet.

1. What is Lean Manufacturing?

• Lean Manufacturing is a production philosophy focused on maximizing customer value while minimizing waste.
• The goal is to improve efficiency, reduce costs, and increase value to the customer by eliminating non-value-added activities (waste).

2. Key Principles of Lean Manufacturing

1. Value:

   • Define value from the perspective of the customer. Anything that does not add value is considered waste.
   • Value Stream: The entire flow of materials and information that is required to bring a product to the customer.

2. Value Stream Mapping:

   • Analyze and map the flow of materials and information to identify areas where waste occurs and improvement is needed.

3. Flow:

   • Create smooth and continuous flow of materials and information without interruptions, delays, or bottlenecks.
   • Avoid batch production, as it can create excessive inventory and long lead times.

4. Pull:

   • Implement a pull system (e.g., Kanban) where products are made only when needed based on customer demand.
   • The pull system avoids overproduction and excess inventory, ensuring production aligns with actual demand.

5. Perfection:

   • The goal is continuous improvement or Kaizen. Always strive to eliminate waste and improve processes in small, incremental steps.

3. The 7 Wastes of Lean Manufacturing (Muda)

1. Overproduction: Making more products than needed, leading to excess inventory.
2. Waiting: Idle time when workers, machines, or materials are waiting.
3. Transportation: Unnecessary movement of materials, products, or equipment.
4. Excess Inventory: Storing more materials or products than needed, causing storage costs and potential waste.
5. Excess Motion: Unnecessary movements by workers (e.g., bending, walking).
6. Defects: Products that do not meet quality standards and require rework or scrap.
7. Overprocessing: Doing more work or adding more features than required by the customer.

4. Lean Tools and Techniques

1. 5S (Sort, Set in order, Shine, Standardize, Sustain):

   • A workplace organization method that helps eliminate waste through better organization and standardization.

2. Kaizen:

   • A philosophy of continuous improvement involving all employees. Small, incremental improvements are made continuously.

3. Kanban:

   • A visual signal or card system that controls the flow of materials based on demand. Used to implement a pull system to ensure that inventory is replenished only when needed.

4. Jidoka (Autonomation):

   • Empowering workers and machines to stop the production line when a defect occurs. This helps prevent defective products and improves quality.

5. SMED (Single-Minute Exchange of Die):

   • A technique for reducing setup times on machinery, enabling faster changeovers and more flexible production.

6. TPM (Total Productive Maintenance):

   • A system of proactive maintenance involving employees at all levels to improve the reliability of machines and reduce downtime.

7. Poka-Yoke (Error Proofing):

   • Techniques that prevent mistakes from happening in the manufacturing process. It’s about designing processes to make it difficult or impossible to make errors.

8. Value Stream Mapping (VSM):

   • A visual tool used to map the current state of processes and identify opportunities for improvement by reducing waste.

9. Heijunka (Level Scheduling):

   • Production leveling to ensure a steady flow of products, avoiding uneven workloads and reducing batch sizes.

5. Lean Manufacturing Benefits

• Reduced Waste: By eliminating waste, Lean reduces inefficiencies, excess inventory, and unnecessary costs.
• Improved Quality: A focus on continuous improvement and quality control ensures fewer defects.
• Increased Efficiency: Streamlining operations and creating smooth flow improves overall productivity.
• Faster Lead Times: With a pull system and better flow, products are delivered faster and more reliably.
• Lower Costs: Reduced waste and better inventory management lead to cost savings.

6. Lean Manufacturing vs. Traditional Manufacturing

7. Steps to Implement Lean Manufacturing

1. Identify Value: Understand what the customer values and define that as the focus of all activities.
2. Map the Value Stream: Analyze the flow of materials and information to find and eliminate waste.
3. Create Flow: Improve process flow to reduce bottlenecks and interruptions.
4. Establish Pull: Implement pull-based systems (like Kanban) to make products only when needed.
5. Pursue Perfection: Foster a culture of continuous improvement (Kaizen) and seek perfection by eliminating waste and improving processes incrementally.

8. Common Lean Metrics

1. Lead Time: Time from order receipt to product delivery. Shorter lead times are the goal.
2. Cycle Time: Time it takes to complete one unit of production.
3. Takt Time: The available production time divided by customer demand. It helps synchronize production speed with customer needs.
4. Inventory Turnover: How quickly inventory is used up and replaced.
5. First Pass Yield (FPY): Percentage of products produced correctly without requiring rework or scrap.
6. Overall Equipment Efficiency (OEE): A metric used to evaluate how effectively a manufacturing operation is utilized.

9. Key Lean Manufacturing Terms

• Value Stream: All the actions (value-creating and non-value-creating) involved in bringing a product from raw materials to the customer.
• Kaizen: Continuous improvement in small, incremental steps.
• Kanban: A visual signaling system used to trigger the pull of materials or parts.
• Jidoka: Automation with a human touch, allowing workers to stop production when issues arise.
• SMED: Reducing the time taken to switch from one production setup to another.
• Poka-Yoke: Mistake-proofing to prevent errors in the production process.
• TPM: Total Productive Maintenance; improving equipment efficiency through proactive maintenance.