Root Cause Analysis for Industrial Cutting Knife Wear

Root Cause Analysis: Accelerated Wear of Final Cutting Knives

Moving from Reactive Replacements to Process Standardization

Operations Strategy Team | January 2026

Problem Statement

Accelerated wear of cutting knives causes frequent unplanned downtime.

Direct negative impact on cutting quality and Overall Equipment Effectiveness (OEE).

Increases maintenance costs significantly due to premature replacements.

This is not a knife problem – it is a process problem that directly impacts availability, costs, and production output.

Business Impact Assessment

⬇ Line Availability: Frequent unplanned stops interrupt workflow.

⬆ MTTR (Mean Time To Repair): Knife replacement is slow and complex.

⬆ Costs: Higher spend on spare parts and specialized maintenance labor.

⬇ Quality: Uneven edges lead to increased scrap rates.

Every knife replacement is a production loss, not just a maintenance activity.

Annualized Cost vs. Target (Hypothetical Model)

Unplanned downtime creates massive 'hidden' costs in lost production opportunity, far exceeding the cost of the knives themselves.

5 Whys Analysis: Tracing the Issue

Why 1: Why is accelerated wear occurring?

Because cutting knives wear out faster than expected.

Why 2: Why do they wear out faster?

Because they operate under high mechanical load and friction.

Why 3: Why are load and friction high?

• Cutting speed is not properly adapted <br>• Knives are not matched to paper grade <br>• Paper tension is not uniform

The Root Cause Discovery

Why 4: Why is there no proper adaptation?

• No clear cutting standard<br>• No defined correlation between product type and parameters<br>• Insufficient real-time process control

ROOT CAUSE

Lack of process standardization and control in the cutting operation—not a knife material issue.

If we only replace knives, the problem will reoccur.

Classification of Root Causes

Process-Related

• Fixed parameters for different products<br>• No differentiation of speeds based on grammage

Technical

• Overly generic knife selection<br>• Cutting geometry not optimized

Maintenance

• Purely reactive strategy<br>• Replacements based on failure, not wear data

Root Cause-Based Solution

Systematic solution, not a local fix. The goal is to reduce interventions, not accelerate replacements.

Define cutting standards based on paper type

Match knife type and speed to product grade

Shift to condition-based maintenance

Measure lifetime using specific KPIs

Implementation Plan

Phase 1: Analysis

Data collection & baseline measurement (2 Weeks)

Phase 2: Standardization

Develop cutting parameters per paper grade (4 Weeks)

Phase 3: Rollout

Training operators & maintenance adjustment (2 Weeks)

Phase 4: Optimization

Monitor KPIs and refine standards (Ongoing)

Expected Results

⬆ OEE & Productivity

⬇ Unplanned Downtime

⬇ Maintenance Costs

⬆ Process Stability

This solution addresses the root cause, improves reliability, and supports sustainable growth.