How an Internal Scoring System Drives Continuous Improvement

Using Lean Six Sigma to prioritize projects, optimize capex, and inform employee recognition.

Lean Six Sigma is a powerful tool for production teams committed to continuous improvement. Viewed as individual activities, however, the overall impact of the improvements it drives may not be obvious. The Continuous Improvement teams in SigmaTron International’s Tijuana, Mexico, facility address this with an annual review meeting that looks both at accomplishments over the past year and year-over-year trends. The top three teams are recognized for their accomplishments.

A visual dashboard displays key metrics. These include:

• Kaizens by engineer
• Area of project impact (quality, efficiency, safety, preventive action or cost)
• Improvement status
• Number of improvements by customer
• ROI vs. investment
• Methodology that identified the improvement need (DMAIC, Gemba, kaizen, lunch and learn, preventative action, 5S)
• Number of projects by priority ranking.

In 2024, the return on investment (ROI) for continuous improvement projects was nearly 300%. Gembas were the largest drivers of improvement need identification. An automotive customer with high volumes and new products drove 10 of the projects. This represented half of the prior year’s number for that customer, because prior projects have stabilized manufacturing processes by automating or fixturing to reduce variation. The rest of the customers were either single digits or 0 in terms of projects. Much of the work is now focused on driving defect instances down to Six Sigma levels or zero defects. The bulk of the projects were quality related. Efficiency improvements were the second largest category, followed by cost, preventive action and safety.

There is also a priority scoring system for project approval. DMAIC (Define, Measure, Analyze, Improve, Control) projects are assigned the highest value, while 5S-related projects are assigned the lowest value. The type of benefit impact (quality, cost, efficiency) also contributes to the score. The speed at which the project can be completed is also a factor. Projects scoring 5-10 have high priority and are coded shades of green, those scoring 3-4 have mid-level priority and are coded shades of yellow, and projects scoring 1-2 are considered low priority and are coded shades of red. The bulk of this year’s projects were high priority. Mid- and lower-level priority projects were also completed, however.

The ROI generated by the improvement is facilitating the purchase of new machining tools, as the ability of tooling/fixturing to reduce process variation was a major contributor to quality improvement across multiple projects. Being able to design and fabricate fixtures in-house reduces the nonrecurring tooling cost to customers and makes it cost-effective to incorporate fixtures more widely throughout manufacturing operations.

The annual review also has a recognition element. Continuous improvement team members progressing in training through project completion receive diplomas recognizing the work they’ve done. The top three teams are honored with a dinner. In addition to the motivational benefits for team members, this recognition also addresses the ISO 9001 requirement for recognition of continuous improvement teams.

Taking time to analyze the overall trends in a continuous improvement program helps pinpoint which activities identify projects with the most impact and demonstrate the program’s effectiveness in stabilizing processes over time. It also helps identify the right investments to continue to enhance quality.

In this case, the continuous improvement activities pursued are driving deeper discussions with customers on best next steps to further improve continuous improvement focus. One area of exploration in these discussions is Operational Excellence (OpEx). Based on the Shingo Model, OpEx is a continuous improvement process that utilizes many Lean Six Sigma core problem-solving tools and areas of focus, but takes a more holistic approach in creating a culture across the entire organization where management and employees are invested in business outcomes and empowered to implement change. Fully implemented, all employees in an OpEx culture understand how their job contributes to the customer’s flow of value and have the tools to fix any abnormalities without direction from management. The leadership aspects of the program also foster improved quality of work life by emphasizing values such as respect and humility.

The electronics manufacturing services (EMS) industry is built on the concept of manufacturing products better, faster and at lower cost than their OEM customers could do. Continuous improvement programs such as Lean Six Sigma and OpEx provide the philosophy and tools to ensure that performance is consistently achieved.

Filemon Sagrero is continuous improvement engineer at SigmaTron International (sigmatronintl.com) in Tijuana, Mexico; filemon.sagrero@sigmatronintl.com.