By
Client: Large Global German Automotive Supplier
Facility: North American Manufacturing Plant (Mexico)
Customer: Toyota Motor Corporation
Industry: Automotive Electronics and Electromechanical Components
The Challenge
A large global automotive supplier was preparing for a Toyota New Supplier Evaluation, one of the most rigorous supplier qualification processes in the automotive industry.
Toyota audits evaluate far more than quality metrics. They assess how well a supplier’s manufacturing system aligns with Toyota Production System (TPS) principles, including:
- Standardized work
- Process discipline at the gemba
- Traceability and containment systems
- PFMEA alignment with production risks
- Change management and process control
- Special process capability
The upcoming audit would include both a full plant operational review and a special process evaluation of welding operations, a process that requires strict process control and statistical capability.
Although the facility already demonstrated strong performance metrics, plant leadership recognized that Toyota audits require tight alignment between documentation, floor practices, and operator understanding.
To ensure readiness, the supplier engaged TKD² to perform an independent operational assessment and prepare the organization for the Toyota audit.
TKD² Approach
TKD² conducted a multi-day operational readiness assessment of the manufacturing facility, evaluating the plant through the same lens used by Toyota Supplier Development engineers.
The review included:
- Production floor walkthroughs
- Documentation and procedure audits
- Operator and leadership interviews
- Review of PFMEA and Control Plan alignment
- Evaluation of traceability systems
- Special process review of welding operations
- Assessment of Toyota Production System practices at the gemba
The objective was to identify any gaps between documented systems and what Toyota auditors would expect to observe on the production floor.
Baseline Operational Performance
The facility demonstrated strong operational performance entering the audit preparation phase.
Customer Quality Performance
- 11 PPM customer defect rate across 15 million parts annually
- 0.37 PPM warranty rate (4 returns in 10.6 million parts)
Supplier Management
- 100% supplier audit completion for four consecutive years
- Supplier audits conducted using VDA 6.3 certified auditors
Traceability Systems
- Full SAP-based material traceability
- Handling unit traceability including consumables
Process Controls
- 100% automated end-of-line testing
- Machine vision inspection at critical stations
- Weld monitoring of current, voltage, displacement, and time
These metrics demonstrated a highly capable manufacturing operation prior to the Toyota audit preparation process.
Risks Identified During the Readiness Review
Despite strong operational performance, TKD² identified several areas that Toyota auditors commonly examine closely during supplier evaluations.
Documentation vs. Production Alignment
Certain PFMEA risk entries did not fully align with actual critical stations on the production line, creating potential audit concerns.
Visibility of Standardized Work
Work instructions were not consistently visible at all production cells, limiting clarity of standardized work at the gemba.
Scrap Containment Discipline
Some scrap containment areas lacked consistent locking or physical control measures.
Change Management Documentation
4M change tracking systems were not consistently implemented across production lines.
Consumable Lot Control
Certain production areas allowed potential mixing of consumable lots.
These issues did not indicate systemic quality problems, but they represented typical areas where Toyota auditors probe supplier discipline and system maturity.
Improvements Implemented
TKD² worked closely with plant leadership to implement targeted improvements prior to the audit.
Process Documentation Alignment
- PFMEA and Control Plans updated to reflect actual production risk points
Standardized Work Visibility
- Work instructions posted at all production cells
- Operator training reinforced with visible standardized work
Quality Containment Improvements
- Scrap handling procedures standardized
- Physical containment controls implemented
Change Management Discipline
- 4M change tracking logbooks implemented across production areas
Consumable Traceability
- Improved lot traceability procedures
- Smaller container sizes introduced to prevent lot mixing
These actions strengthened the plant’s ability to demonstrate Toyota Production System discipline directly on the production floor.
Special Process Audit Preparation
The Toyota audit also included detailed evaluation of welding operations classified as special processes.
The facility already demonstrated strong process controls, including:
- RFID-based automatic welding parameter loading
- Password-protected welding program management
- Real-time weld monitoring
- Automatic containment of non-conforming welds
- Golden and Red Rabbit validation checks
TKD² supported additional preparation by:
- Aligning PFMEA and Control Plans with welding process risks
- Improving traceability of welding fixtures
- Strengthening documentation of validation checks
- Preparing operators to clearly explain process controls during the audit
Results
Following the readiness improvements and preparation efforts, the facility successfully completed the Toyota New Supplier Evaluation audit.
As a result, the supplier was approved as a qualified Toyota supplier and awarded new production business.
The preparation effort ensured the facility was able to clearly demonstrate:
- Alignment with Toyota Production System expectations
- Strong process discipline at the production floor
- Robust traceability and containment systems
- Controlled special processes with documented capability
The successful audit outcome validated both the plant’s operational capability and the effectiveness of the preparation process.
Value Delivered by TKD²
TKD² provides independent readiness assessments for automotive suppliers preparing for major OEM supplier audits and new business opportunities.
By combining manufacturing expertise with an understanding of Japanese OEM audit expectations, TKD² helps suppliers identify and close risks before customer evaluations occur.
This approach enables suppliers to confidently demonstrate their operational systems and secure new business opportunities with global OEMs.
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