Case Study: On‑Site Supplier Due Diligence and Continuous Improvement in Southeast Asian Manufacturing

Case Study: On‑Site Supplier Due Diligence and Continuous Improvement in Southeast Asian Manufacturing

Context

Evahan recently supported an Australian lighting infrastructure company in undertaking on‑site due diligence of its existing offshore manufacturing supplier in Vietnam.

The engagement followed the identification of recurring quality issues across delivered product, including:

• inconsistent weld quality on manually welded seams following robotic processes
• defects in surface preparation impacting downstream coating performance
• variability in galvanising and coating outcomes
• damage arising from poor packaging and container loading practices

These issues were not isolated. They were systemic.

The challenge was not simply to identify non‑conformances.

The challenge was to understand how quality was actually being created — or compromised — inside the supplier’s manufacturing environment, and to establish a pathway to improve it.

Evahan Insight

Desktop review and email‑based corrective actions were not going to resolve the issue.

The only viable approach was:

• on‑site engagement
• direct observation of manufacturing processes
• structured assessment of actual practices (not documented claims)
• and working alongside the supplier to define practical improvements

This required operating in an environment where:

• English was limited or not spoken
• process control was largely informal
• quality outcomes were driven more by operator practice than system discipline

Evahan leveraged prior experience in establishing manufacturing operations for Australian‑owned companies in Thailand to navigate this environment effectively.

What Evahan Did

Evahan worked directly with the client’s leadership team on‑site in Vietnam to:

Supplier Due Diligence

• Conduct structured factory assessments of the existing supplier and a potential alternative supplier
• Evaluate welding practices, coating processes, material handling, and packaging protocols
• Assess the supplier’s actual quality management practices versus documented systems

Process Mapping and Visibility

• Develop a full manufacturing process map from raw material receipt through to container loading
• Identify critical stages where quality is created or lost, including:
  • post‑robotic manual welding
  • surface preparation prior to galvanising and coating
  • galvanising process control
  • paint and powder coating application
  • packaging and containerisation

Continuous Improvement Program Development

• Establish a structured Continuous Improvement (CI) framework with the supplier
• Define practical control points and inspection requirements
• Introduce realistic acceptance criteria aligned to Australian standards and customer expectations

Welding and Coating Control

• Assess welding capability against required standards
• Define a “sufficient and defensible” welding compliance position
• Identify gaps in procedures, qualifications, and execution
• Develop a pathway to close those gaps through targeted improvement rather than over‑engineering

Packaging and Logistics Correction

• Redesign packaging and container loading protocols to prevent damage in transit
• Shift from ad hoc bundling to controlled handling methods

Strategic Supplier Positioning

• Support evaluation of a secondary supplier pathway
• Enable informed decision‑making based on capability, responsiveness, and improvement potential

Outcome

The engagement transitioned the supplier relationship from:

• an outcome‑based acceptance model

to:

• a process‑informed manufacturing partnership

This delivered:

• clear visibility of how product quality is created within the supply chain
• identification of root causes of recurring defects
• a structured Continuous Improvement program embedded at the supplier level
• the ability to manage quality proactively, rather than reactively

Importantly, it established a practical pathway to lift quality performance over time, rather than attempting to enforce compliance through documentation alone.

Evahan Position

Complex supply chain issues are not resolved through remote management or document exchange.

They are resolved on the floor.

Effective due diligence requires:

• direct observation
• structured thinking
• and the ability to work within different cultural and operational environments

Evahan’s approach combines:

• on‑site engagement
• practical process design
• and continuous improvement implementation

to turn supplier relationships into controlled, repeatable manufacturing outcomes.