Overview
Apex Precision Coatings Ltd., a specialist provider of parylene coating services, faced a period of growing operational strain. Lead times were stretching to nearly three weeks, defect rates were well above expectations, and workflow performance was both unstable and unpredictable. These challenges were largely due to the company’s complex processes, where the intricacy of multi-stage operations contributed to inefficiencies and operational difficulties. With customer satisfaction slipping, the company needed an urgent change in strategy and execution.
To address this, Apex launched a Lean Six Sigma Black Belt project led by Process Engineer Daniel Hart, who was simultaneously completing Leanscape’s structured Black Belt programme. Unlike traditional training, the programme integrates personalised 1-to-1 mentoring, enabling real-time feedback, guidance, and strategic thinking support. The results were transformational.
Background and Industry Context
In today’s fast-paced business environment, the drive for operational excellence is more critical than ever. Organizations across different industries are under constant pressure to enhance operational efficiency, reduce operational costs, and deliver superior customer satisfaction. This relentless pursuit is fueled by rapidly shifting market demands and ever-evolving customer expectations, making it essential for companies to adapt quickly and effectively.
Lean Six Sigma methodologies have become a cornerstone for organizations aiming to streamline processes and achieve continuous improvement. Certifications such as Six Sigma Green Belt and Sigma Master Black Belt equip professionals with the skills needed to optimize production processes, refine business processes, and elevate service delivery standards. By leveraging these methodologies, companies can not only reduce waste and variation but also gain a competitive advantage in their respective markets.
The integration of digital tools and digital transformation initiatives further accelerates process optimization and enhances service quality. These technologies enable real-time data analysis, improved decision-making, and greater transparency across the supply chain. As a result, organizations are better positioned to meet customer expectations, respond to market demands, and sustain high levels of customer satisfaction. In this context, Lean Six Sigma and digital transformation are not just operational strategies—they are essential drivers of long-term business success.
The Challenge: Achieving Operational Efficiency
Apex operated a multi-stage process involving masking, coating, curing, demasking, inspection, and shipping. Although technically complex, the biggest issues stemmed from flow, variation, and quality defects rather than the coating chemistry itself. Inefficiencies in internal processes were contributing to operational strain, with workflow bottlenecks and inconsistent procedures impacting overall performance.
- Lack of scheduling control was causing delays in the workflow, making it difficult to predict lead times and manage customer expectations.
Key problems included:
- Lead times of 15–20 working days against a target of 7–12, with extended processing times impacting overall performance
- Right-First-Time quality of just 70%, driven by FOD, fingerprints, voids, and masking inconsistency
- Over 75% of cycle time spent waiting, queuing, or moving product
- 60+ metres of unnecessary movement per batch due to layout constraints
- High operator variation between shifts
- Lack of scheduling control, causing inventory buildup and hidden bottlenecks
In short: the system produced value only part of the time. The rest was waste.
Approach: Combining DMAIC with Personalised Coaching
Daniel began applying the DMAIC methodology while receiving continuous 1-to-1 mentoring from a Leanscape Master Black Belt. This combination ensured analytical depth, clarity of thought, and structured progression at each stage, leveraging lean methodologies as part of the Lean Six Sigma approach to drive process improvement and operational efficiency.
Define Phase
- Clear problem and goal statement established
- Voice of the Customer highlighted the urgency around reliability and predictability
- SIPOC mapping revealed a fragmented process with excessive handovers, underscoring the need for effective process design. By applying structured process design methodologies at this early stage, the team was able to identify improvement opportunities and engage key stakeholders in redesigning workflows.
Measure Phase
Daniel implemented a robust measurement strategy covering lead time, defects, DPMO, WIP, operator performance, layout-driven delays, and key order processing metrics to assess workflow efficiency.
Key findings:
- Lead time distribution was left-skewed (most batches 15–18 days)
- Process capability: Cpk = –0.79, incapable of meeting customer expectations
- One batch’s DPMO exceeded 200,000, a < 2 sigma level
- Spaghetti diagrams showed excessive movement between floors
- ANOVA confirmed defects added ~10 days to processing time
- Order processing metrics revealed bottlenecks contributing to fulfillment delays
Mentoring during this phase focused on:
- Validating the measurement system
- Selecting correct statistical tests
- Structuring data collection for reliability
- Using visuals to communicate insights clearly
Analyse Phase: Finding What Really Matters
With data in place, root cause analysis identified major contributors: the goal of this analysis is to optimize processes by addressing the identified root causes.
1. Flow breakdowns
The process worked in a push system, with uncontrolled WIP building between departments. Queues, not capacity, were driving delays. Repetitive tasks were common, further contributing to inefficiencies in the process flow.
2. Defects and rework
In the manufacturing process, voids, FOD, and fingerprints were the top defects. Rework extended lead times by up to 10 days.
3. Skill variation and training gaps
Shift-to-shift performance fluctuated significantly. Late shifts often relied on early-shift specialists, creating dependencies that slowed coating. Implementing sigma courses can help address these training gaps by providing structured learning paths and certifications, ensuring all operators develop consistent skills and expertise.
4. Environmental and ergonomic issues
Vibration affected microscope stability in masking, leading to errors.
Cleanliness standards varied, contributing to contamination defects.
5. Weak visual management and planning controls
There was no real-time WIP visibility, forcing constant manual chasing.
By introducing visual management and planning controls, teams can standardize procedures, which is essential for ensuring consistent execution across departments. This standardization helps reduce variation in processing times and promotes smoother, more predictable workflows.
Mentoring support during Analyse helped Daniel contrast correlation vs causation, run hypothesis tests, and build a compelling narrative for leaders.
Inventory Management and Control
Effective inventory management is a cornerstone of operational efficiency, directly influencing production costs, inventory holding costs, and a company’s ability to respond to fluctuating market demands. By implementing robust inventory control systems and applying Lean Six Sigma principles, organizations can significantly reduce waste, shorten lengthy development cycles, and optimize resource allocation.
Advanced analytics and digital tools now provide real-time visibility into inventory levels, enabling more accurate forecasting and minimizing the risks of stockouts or excess inventory. This level of insight supports more agile decision-making and ensures that production processes remain aligned with actual market needs, rather than being driven by outdated or inaccurate data.
A continuous improvement culture is essential for sustaining these gains. Prioritizing employee engagement and ongoing training ensures that all team members are equipped to identify inefficiencies and contribute to process improvements. When organizations embrace Lean Six Sigma methodologies and foster a culture of continuous improvement, they achieve not only lower operational costs and improved service delivery but also a stronger market position and higher customer satisfaction.
Improve Phase: Designing Solutions That Stick
Cross-functional workshops generated a wide set of improvement ideas, focusing on practical strategies to address the identified challenges. After weighted scoring, Daniel—now confident in structured facilitation—prioritised three core improvement areas:
1. Flow Excellence
- Supermarkets introduced between Mask → Coat → Demask, streamlining process flow and contributing to overall efficiency.
- Kanban triggers implemented to shift from push to pull, optimizing workflow for improved overall efficiency.
- Daily WIP caps enforced, supporting continuous improvement and enhancing overall efficiency.
2. Quality Reliability
- Operator upskilling
- Standardisation of masking and demasking
- 5S deployment across all workstations
- Enhanced cleanliness controls, resulting in measurable quality improvements such as reduced defects and increased product reliability
3. Workforce Capability
- Clear role expectations
- Competency tracking
- Improved handovers between shifts
A four-week pilot on a single product family validated the improvements.
Quantitative Results
| Metric | Before | After | Improvement |
|---|---|---|---|
| Lead Time | 16 days | 9 days | 44% faster |
| Defects (DPMO) | 220,000 | 165,000 | 25% reduction |
| Monthly Throughput | £40k | £90k | 125% increase |
Statistical validation (two-sample t-test, p < 0.0001) confirmed improvements were significant.
SPC charts demonstrated the new process was stable.
These results delivered significant improvements in key performance metrics, including substantial cost savings and enhanced operational efficiency. The project helped improve profitability by reducing waste and increasing throughput, demonstrating the measurable financial impact of Lean Six Sigma coaching.
Qualitative Results
- Strong operator engagement and ownership
- Cleaner, structured work environment
- Clear visual workflow and WIP transparency
- Improved shift continuity
- Faster issue escalation and resolution
- Enhanced customer satisfaction through improved process quality and operational efficiency
The Hidden Advantage: 1-to-1 Coaching
One of the strongest outcomes of this project was Daniel’s transformation from a technically skilled engineer to a confident improvement leader.
How the coaching shaped success
- Ensured correct use of analytical tools
- Supported communication strategies for senior leadership
- Improved workshop facilitation techniques
- Built confidence in statistical decision-making
- Accelerated personal development and change leadership capability
For Apex, this meant the project did not just deliver results—it built internal capability.
Sustaining and Improving Results
Achieving operational excellence is not a one-time event but an ongoing journey that demands sustained focus and commitment. To maintain and build upon improvements, organizations must develop strategies and systems that support long-term sustainability. This includes systematically addressing quality issues, minimizing human error, and continuously enhancing service quality.
Lean Six Sigma methodologies, supported by certifications such as Sigma Green Belt and Six Sigma Black Belt, provide a structured framework for driving continuous improvement. The integration of digital tools enables organizations to track progress, analyze process performance, and quickly identify new opportunities for optimization. These technologies also facilitate data-driven decision-making, ensuring that improvements are both measurable and sustainable.
Cultivating a culture of continuous improvement is equally important. When employee engagement and training are prioritized, teams are empowered to take ownership of processes and drive ongoing enhancements. This approach leads to significant and lasting improvements in operational efficiency, customer satisfaction, and overall competitiveness. Ultimately, organizations that commit to continuous improvement and leverage Lean Six Sigma methodologies are better positioned to achieve long-term sustainability and enhanced profitability.
Key Takeaways and Best Practices
Achieving operational excellence requires a holistic approach that integrates the optimization of production processes, business processes, and supply chain operations. Lean Six Sigma methodologies, combined with the strategic use of digital tools and technologies, provide a powerful foundation for continuous improvement and process optimization.
Best practices include fostering a continuous improvement culture where employee engagement and training are central, leveraging advanced analytics to drive decision-making, and implementing robust inventory management systems to reduce lead times and improve quality standards. Companies should also focus on reducing defects, minimizing waste, and optimizing resource allocation to lower operational costs and enhance customer satisfaction.
Applying Sigma practices such as Failure Mode and Effects Analysis helps organizations proactively identify and mitigate risks, while strong inventory control supports customer retention and improved profitability. By embracing these strategies and maintaining a relentless focus on continuous improvement, organizations can compete effectively, achieve long-term sustainability, and deliver superior service quality in an increasingly demanding marketplace.
Conclusion
The Lean Six Sigma Black Belt project at Apex Precision Coatings demonstrates the power of combining rigorous methodology with personal coaching:
- Lead times cut nearly in half
- Quality defects significantly reduced
- Throughput more than doubled
- Operator culture and ownership transformed
- Long-term capability built within the organisation
Apex now operates with greater stability, higher predictability, and stronger customer confidence. These improvements have helped Apex recover lost revenue opportunities, maintain and even increase market share, and significantly impact the company’s overall performance and competitiveness. The project continues to serve as a blueprint for future improvements across the organisation.
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