EDM Process Optimization: Reducing Scrap & Recovering Profit Margins

Overview


A cutting tools SME using Electrical Discharge Machining (EDM) faced rising defects and scrap, causing 15% cost overruns on recent orders. The issue stemmed from unvalidated internal process rules, leading to inefficiencies. AEM Consulting was engaged to optimize their EDM process and restore profitability.

The Challenge

The client's primary challenge was the escalating scrap and defect rates across multiple EDM machines. This directly led to increased production costs, longer machining times, and unreliable output quality.

Key issues includes:

Continuing with these flawed parameters would have led to further financial losses, unreliable product quality, and diminishing competitiveness.

AEM's Investigation & Root Cause Discovery

AEM began performing a detailed diagnostic to scientifically validate the machining issues.

Process Diagnosis & Hypothesis Testing

AEM performed statistical hypothesis testing to confirm that:

This confirmed that the process itself is not human error, was the source of quality issues.

Designed Experiments (DOE) with Orthogonal L9 Array

AEM conducted a structured Design of Experiments (DOE) using Taguchi Orthogonal L9 Array, varying key EDM parameters such as: Pulse ON time, Pulse OFF time, Current, Voltage, and Wire feed/discharge rate

This enabled precise, controlled experimentation to measure the effect of each factor on: Material Removal Rate (MRR), Surface finish, Dimensional accuracy, Defects occurrence

DOE revealed the exact parameter combination that minimized variation and maximized machining performance.

SPC Charts & Process Stability Analysis

AEM used Statistical Process Control (SPC) charts to:

The post-intervention control charts showed significantly tighter process control and near-zero defect trends.

Validation & Controlled Trials

Multiple validation cycles were run using the optimized parameters to ensure:

This step ensured the new process settings were robust in real operations, not just experimental conditions.

The AEM Solution

AEM deployed a structured, scientific approach to fully optimize the EDM process.

Root Cause Confirmation

Incorrect, unvalidated EDM parameters were confirmed as the primary driver behind scrap, poor accuracy, and long cycle times.

Experimental Optimization

AEM designed and executed a complete DOE framework using the Orthogonal L9 Array, enabling systematic variation and precise measurement of EDM performance.

This allowed the team to determine: Main effects of each parameter, Interaction effects, and Optimal balance between removal rate and quality

Optimum EDM Parameter Set Identified

A precise, validated parameter combination was established for every EDM machine, ensuring: Consistent machining, Maximum removal rates, Minimum surface defects, and Accurate dimensional control.

Implementation, Standardization & Training

AEM rolled out the optimized settings across all machines and implemented:

This ensured sustainable adoption and repeatability.

Results & Impact

Quality Improvement

Defects & Scrap Reduction
90% Reduction
Drastically lowered material wastage
Rework & Cost Losses
95% Reduction
Eliminated existing 15% cost overrun
Stable, predictable, defect-free machining

Operational Performance

Machining Cycle Time
Significantly Faster
Higher material removal rates
Throughput & Delivery Speed
Improved
Increased production capacity
Operational Efficiency
High & Consistent
Predictable EDM performance

Process Optimization

Energy Usage
Optimized
Lower electricity & operating costs
Process Standardization
Scientifically Validated
Ensures long-term quality & consistency
Data-driven optimization replaced trial-and-error machining

Outcome Summary

We delivered a complete scientific overhaul of the client's EDM process using hypothesis testing, DOE with Orthogonal L9 Array, and SPC-based control systems.

By identifying the optimal machining parameters and enforcing process standardization, the client achieved:

Ready to enhance your efficiency?

For expert assistance in process optimization, defect reduction, and enhancing manufacturing efficiency in complex industrial operations, please contact AEM Consultancy.