Iris Optics
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Supplier CorrelationOptical Metrology

Cross-Site Test Correlation

Aligning measurement results across internal and supplier sites.

Challenge

Inconsistent measurement results between the OEM's internal labs and the overseas supplier sites were causing ambiguity in yield and quality decisions.

Approach

We implemented a rigorous correlation program using golden samples, reference artifacts, and correlation matrices. We established strict data governance and reviewed the fundamental measurement methods at both sites.

Outcome

The correlation program improved comparability, reduced ambiguity, and ensured that both the OEM and the supplier were speaking the same language when it came to optical quality.

Background

When optical hardware is designed in one country and manufactured in another, test correlation is paramount. If the OEM’s lab measures a part as a “pass” and the supplier’s factory measures the same part as a “fail”, the entire supply chain breaks down.

The Challenge

The client was facing significant discrepancies in optical measurement results between their internal R&D lab and their primary overseas supplier. This led to endless debates over yield, quality escapes, and root causes, significantly slowing down the NPI schedule.

The Approach

We deployed a comprehensive cross-site correlation strategy:

  1. Methodology Review: We first audited the measurement methodologies at both sites, identifying subtle differences in alignment, calibration, and environmental controls.
  2. Golden Samples & Artifacts: We established a set of stable “golden samples” and reference artifacts that traveled between the sites to baseline the equipment.
  3. Correlation Matrix: We ran Gage R&R and correlation studies, building a matrix that quantified the offsets and scaling differences between the measurement stations.
  4. Data Governance: We implemented a data governance policy to ensure that both sites were analyzing the raw data using identical algorithms and parameters.

The Outcome

By quantifying and correcting the differences between the measurement sites, we eliminated the ambiguity in quality decisions. The OEM and the supplier were finally able to trust each other’s data, allowing the team to focus on resolving actual hardware issues rather than arguing over measurement discrepancies.