Deep Dive: Lean Automation in Practice — From 1/N to the Thousand-Ton Press Revolution
In the era of Smart Factories, many organizations still cling to the conventional assumption that “bigger machines equal higher production and better efficiency.” However, in the world of Lean Automation, this belief is being systematically challenged.
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In this article, Solwer takes you deep into the application of the 1/N concept, demonstrating how a 3,000-ton press machine can be reduced to just 600 tons while maintaining output. We will explore the “engineering rationale and business impact” of this transformation.
1/N Philosophy: When “Less” Becomes “More” (Less is More)
The 1/N concept is not merely a process improvement tool; it is a “systems thinking framework” that directly challenges traditional factory design.
At its heart is a simple yet powerful question: “Can we reduce total complexity (N) to leave only what truly generates value (1)?”
1. From Optimization to System Redesign
Most organizations misunderstand Lean, viewing it merely as “Optimization”—such as:
- Reducing setup times
- Minimizing scrap
- Improving OEE
From a 1/N perspective, these are still just improvements within an existing system. 1/N asks:
- Are these five steps truly necessary?
- Why do we need three machines?
- Are we addressing the root cause or just the symptoms?
The answer often leads to “eliminating steps” rather than “speeding them up.”
This is the difference between:
- Optimization: Making the existing process better.
- Redesign: Transforming the process entirely.
2. 1/N and the Foundation of Lean Thinking
The 1/N concept aligns directly with the core principles of the Toyota Production System (TPS).
TPS has two main pillars:
- Just-in-Time (JIT) → Produce only what is needed, when it is needed.
- Jidoka → Stop the line when problems occur to maintain quality.
What makes TPS truly powerful is the concept of “eliminating waste.”
3. Muda: The True Enemy of Efficiency
In Lean, we categorize waste as Muda, which includes seven main types:
- Overproduction
- Waiting
- Transportation
- Overprocessing
- Inventory
- Motion
- Defects
4. 1/N = Structural Muda Elimination
The differentiator of 1/N is that it does not just “reduce waste”; it designs a new system where waste does not exist from the start.
Examples:
- From 4 processes to 1
- From 3 machines to 1
- From Batch processing to One-piece Flow
This is the act of “deleting N” to leave “1.”
5. The Power of Simplification
When a system is downsized:
Complexity Reduction → Error points decrease exponentially.
Stability → Process control becomes easier.
Flow Efficiency → No bottlenecks between stages.
Hidden Cost Removal → Reduced WIP and energy loss.
6. Mindset Shift: The Hardest Part of 1/N
The biggest obstacle is not technology, but “conventional wisdom”—such as:
- Bigger is safer
- More steps equal easier control
- Having a lot of buffers is good
In reality, these are “buffers of system ignorance.” 1/N forces us to return to understanding the “physics of the process” truly.
Case Study: Reducing a 3,000-Ton Press to 600 Tons
This case study is not about mechanically “shrinking” a machine; it is about completely redefining the “Metal Forming Equation,” from required force to material flow dynamics within the die. The starting point: Redefining “Actual Force.”
The Beginning: Not just reducing the machine, but asking new questions about “Actual Force.”
The project to reduce a press from 3,000 tons to 600 tons did not start with a goal to “shrink the machine.” It started by asking the most fundamental question of the metal forming process.
That question was: “How much force do we actually need, and how can we make it lower?”
When the question changed, the entire mindset changed immediately. Instead of “machines must be big for safety,” it shifted to looking at the “physics of the process” to see where the actual force is and what hidden waste exists.
Key Steps in System Transformation
Starting from the question of “Actual Force,” the engineering team broke the analysis into four approaches, focusing on reducing force requirements at the source rather than merely increasing machine capacity.
1. Analyze Actual Forming Load
Measurements and simulations (Simulation + Empirical Test) revealed that the “Effective Load” was significantly lower than the machine’s capacity.
1. Analyze Actual Forming Load
Measurements and simulations (Simulation + Empirical Test) revealed that the “Effective Load” was significantly lower than the machine’s capacity.
Force Loss Mechanism
- Structural Loss: Some force never reaches the workpiece, used instead for:
- Press Frame stretching
- Elastic deformation of the structure
- Vibration absorption
- Overdesign for Safety Margin: Presses are often designed to:
- Handle worst-case scenarios
- Allow for material variation
- Allow for tooling wear
Resulting in “excessive capacity” locked in the system.
- Friction & Inefficiency in the System
Force loss occurs due to:
- Friction between the workpiece and die
- Non-optimal lubrication systems
- Non-linear force transmission
2. Advanced Material Flow Engineering
When understanding that “force isn’t lost, but used incorrectly,” the team shifted from “adding force” → to “controlling material flow.”
This is what made the reduction from 3,000 tons → 600 tons actually possible.
Core Concept: Change Force Problem → Flow Problem
Instead of “pushing through,” shift to “designing material flow along the desired path.”
Techniques used
- Draw Bead Design
Helps control sheet metal flow (Sheet Metal Flow Control):
- Reduces wrinkling
- Controls tension distribution
- Progressive Forming
Instead of heavy single-stage hits → change to “continuous multi-step flow.”
Results:
- Reduces peak load
- Reduces shock load
- Lubrication Optimization: Adjusting:
- Coefficient of friction
- Lubricant type
- Application method
Significantly reduces resistance between the material and the die.
3. Single Shot Integration
One of the most critical breakthroughs was “re-architecting the production structure” to complete everything in one step, rather than letting the part travel through multiple machines as before.
In traditional production, the forming process was clearly separated, with each stage running on different machines, leading to unnecessary complexity and waste.
Previously, the process was divided into:
- Trim (cutting workpiece edges)
- Pierce (hole punching)
- Bend (folding)
Operating across 3-4 machines caused transport movement, waiting times, and increased risks of tolerance stack-up with each part transfer.
From a Lean perspective, this creates “Waste” in many forms, including Transportation, Waiting, and Overprocessing—all hidden costs that don’t add value.
New Strategy: Die Integration Strategy
Combine everything in a: “Single Die + Single Stroke Execution.”
Engineering Impact
- Reduced Handling Error
No part transfer between machines → reduced human + mechanical error.
- Reduced Tolerance Stack-up: When all processes share the same reference:
- Cumulative error is eliminated.
- Dimensional accuracy is significantly improved.
- Increased Process Stability: Due to reduced process variables.
4. Compact Machine Layout
When the load is reduced and processes are merged, the final step is “designing the new machine according to the new physics.”
Design Principles
- Reduced Travel Distance
Less movement → lower error opportunities.
- Reduced System Inertia
Lighter structures → more precise acceleration/stopping → reduced dynamic energy loss.
- Increased Stiffness per Unit Size: Even if the machine is smaller, it must be:
- More rigid than before
- Less deformation than before
Systemic Results
- Machine footprint reduced
- Maintenance reduced
- Energy consumption per cycle was reduced
Business Results
When the entire system is redesigned based on “Actual Required Force,” not “Safety Margin Force,” changes occur across multiple dimensions simultaneously.
- Machine size reduced by ~80% from 3,000 tons to 600 tons.
- Energy consumption was significantly lowered due to reduced peak load and idle loss.
- Workpiece quality is more stable by reducing errors from moving across multi-step processes.
- Factory layout is more compact, making production flow continuous and highly efficient.
Reducing size isn’t just “making the machine smaller,” but “making the actual force requirement smaller.” When the core force is understood correctly, everything from machinery to energy and layout can be redesigned for simultaneous high efficiency.
Business Impact Summary
| Metric | Before | After |
|---|---|---|
| Machine Size | 3,000 Tons | 600 Tons |
| Energy | Very high | Significantly reduced |
| Process steps | Multi-step | Single Shot |
| Defect rate | Higher | Lower |
