Industry Type: Manufacturing
Department: Quality Management
Company Name: Excelitas Noblelight
Project Type: Green Belt Project
Project Duration: 5 months
Financial Benefit: Approx. $17,000 annually
Reducing Product Reject Rates: A Hands-On Approach with Lean Six Sigma
In the world of manufacturing, product quality and cost efficiency go hand-in-hand. Excelitas Noblelight, a producer of advanced photonics-based light sources used in fields like analytical measurement, heating, and disinfection, faced a familiar challenge: scratched components. These scratches were not only affecting product quality but also adding unnecessary costs due to high reject rates. Applying Lean Six Sigma methods, the team set out to identify and resolve the root causes of these defects, ultimately achieving significant improvements in quality and cost savings.
Understanding the Challenge
For Excelitas Noblelight, scratched lamps were causing a high reject rate, translating to over $54,000 annually in wasted products. The project’s primary goal was to reduce this reject rate by at least 25%, with a target of 0.27%, creating an annual savings of around $17,000. The stakeholders included the company’s Quality Manager and the Supply Chain Manager, whose vested interests ensured project alignment with the company’s broader goals.
Scoping the Project
Defining the problem with a measurable goal is a Lean Six Sigma cornerstone. Here, the Green Belt team used a Critical to Quality (CTQ) flow-down method, which helps teams define what factors are essential to meet quality standards. By using a SIPOC analysis—a tool for identifying Suppliers, Inputs, Process, Outputs, and Customers—the team could better understand what aspects of the lamp production process to prioritize.
The main objective was to identify the root causes of the scratches and implement process adjustments to prevent future defects. In line with Lean Six Sigma’s DMAIC methodology (Define, Measure, Analyze, Improve, and Control), this structured approach allowed for step-by-step problem-solving.
Creating a Diverse Project Team
Building an effective team with various expertise areas is crucial to success in any Lean Six Sigma project. For this project, team leader Joshua Spellmore assembled a small core team with expertise relevant to lamp production and quality management. He also ensured access to additional resources as needed, creating a dynamic support network for specialized tasks.
Root Cause Analysis
In the Analyze phase, the team used tools such as Fishbone Diagrams (also known as Ishikawa diagrams) to brainstorm possible causes of the scratching issue. This visual tool helped organize potential causes under categories like Methods, Machines, Materials, and Environment, encouraging team members to think broadly.
Additionally, the team applied the 5 Whys method, which involves asking “Why?” repeatedly to drill down into the underlying causes of a problem. After thorough analysis, the team discovered that quartz particles in the trays used to transport the lamps were contributing significantly to the scratches.
Implementing Practical Solutions
Once the root cause was identified, the team moved to the Improve phase, focusing on practical, implementable solutions. Here, the solution was clear: establish a cleaning protocol for trays at multiple stages in the production process to eliminate the quartz particles causing the scratches.
To ensure the effectiveness of this solution, a pilot solution was introduced to observe its impact. The pilot yielded impressive results, reducing the reject rate by 50%—far surpassing the initial 25% reduction target.
Control Plan and Sustainability
Lean Six Sigma emphasizes not only immediate improvements but also sustainable long-term results. After implementing the changes, the team created a comprehensive control plan to maintain the reduced reject rate. This plan included:
Weekly Monitoring: Regularly reviewing reject rates to quickly identify any deviations from the target.
Standard Operating Procedures (SOPs): Documenting the new tray-cleaning protocol and other essential steps to standardize processes.
5S Methodology: Implementing 5S (Sort, Set in order, Shine, Standardize, Sustain) principles to keep work areas organized and ensure easy compliance with the new protocols.
Daily Gemba Walks: A Gemba walk involves managers and team leaders observing the production process firsthand to spot any areas needing improvement.
These steps helped embed the changes within the organizational processes, ensuring the reject rate stayed below 0.24% and secured annual savings of around $17,000.
Key Challenges and How They Were Overcome
Every project encounters hurdles, and this one was no different. Spellmore’s team faced several issues, such as:
Resource Allocation: With limited operator availability, ensuring enough time for sampling was a challenge. To address this, the project lead proactively coordinated with supervisors to align resources with project requirements.
Resistance to Change: Some operators initially resisted the new protocols, fearing blame for defects. To counter this, Spellmore communicated the project’s goals clearly, emphasizing that the aim was to improve processes, not scrutinize individual performance. This transparent approach helped alleviate concerns and fostered cooperation.
By effectively managing these obstacles, the team maintained morale and engagement, which was critical to the project’s overall success.
Results and Financial Impact
The project’s success was evident in the metrics. Initially, the reject rate from scratches was at 0.36% of total production. After implementing the new protocols, the rate dropped to 0.18% during the pilot phase and settled at an average of 0.24% after full implementation. This substantial improvement resulted in an annual cost reduction of approximately $17,000, a clear demonstration of Lean Six Sigma’s financial impact.
Lessons Learned and Best Practices
Reflecting on the project, Spellmore highlighted several valuable lessons:
Define the Project Scope Carefully: A clear project scope ensures that efforts are directed at areas with the most significant impact. This project benefited from thorough upfront planning, which allowed the team to target the primary contributors to product rejects.
Effective Communication Builds Cooperation: Transparent communication with operators and supervisors was essential. By explaining the project’s intent and how it would benefit the entire team, Spellmore fostered a culture of collaboration and minimized resistance.
Regular Monitoring Ensures Lasting Results: The control plan, with its routine checks and Gemba walks, ensured that the project’s improvements would be sustained. Lean Six Sigma emphasizes ongoing accountability, which was key to maintaining reduced reject rates in this case.
Conclusion: Practical Lean Six Sigma in Action
For those new to Lean Six Sigma, this project offers a tangible example of its potential. By systematically identifying and eliminating a key cause of product defects, Excelitas Noblelight not only improved product quality but also secured significant financial savings.
The structured DMAIC approach, combined with a clear focus on measurable outcomes, showcases Lean Six Sigma’s ability to transform challenges into opportunities. Whether you’re working in manufacturing, healthcare, or any other industry, Lean Six Sigma provides a toolkit that’s adaptable, effective, and focused on sustainable improvement.
