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Manufacturing Lean Six Sigma

€2.4M Waste Eliminated
in 11 Weeks

A French Tier-2 automotive supplier was losing €6.2M annually to rework, overprocessing, and waiting time. SNZ Sona's DMAIC intervention delivered €2.4M in verifiable savings within a single quarter.

38%

Cost Reduction

€2.4M

Annual Waste Eliminated

11

Weeks to Results

The Challenge

A margin crisis hiding in plain sight

Our client — a 600-employee Tier-2 automotive components supplier near Lyon — had seen margins compress by 14% over three years. Internal process reviews consistently identified 'quality issues' as the root cause, but corrective actions never lasted beyond 6 months. When we arrived, 22% of production output required rework before shipping.

The true cost of this defect rate, including the hidden costs of waiting, transportation, and overprocessing, exceeded €6.2M per year. Yet the production floor was busy — operationally the plant looked active. The problem was systemic, embedded in processes, not people.

Leadership needed more than another quality review. They needed root causes identified, quantified, and permanently resolved — with a team that could execute quickly and leave the capability behind.

22% of production output required rework

Baseline defect rate at engagement start — before any intervention

Our Approach

DMAIC from diagnosis to control

D

Define

Week 1–2

Stakeholder interviews, process boundary mapping, 47 data points collected across 3 production lines. Project charter signed off with Operations Director and Production Manager jointly.

M

Measure

Week 2–4

Current state Value Stream Map completed. Defect rate baselined at 22.3% across all shifts. Cpk analysis on 12 critical dimensions identified 4 statistically incapable processes. Gauge R&R study revealed 31% measurement system variation.

A

Analyse

Week 4–6

Root cause analysis via fishbone diagrams and 5-Why methodology. Primary cause identified: inconsistent fixture calibration across shifts. Secondary cause: shift handover knowledge gap allowing deviations to carry forward undetected into the next production run.

IC

Improve & Control

Week 6–11

Fixture calibration SOP redesigned with photographic visual aids. Hourly interval checks introduced with documented sign-off. Power BI quality dashboard built to surface real-time deviations to shift supervisors. Shift supervisor training delivered across all three production lines.

Verified Results

Measurable. Documented. Sustained.

38%

Reduction in total production cost per unit

Verified against pre-engagement cost baseline across all three production lines

81.6%

Defect rate improvement — 22.3% down to 4.1%

Measured using the same sampling methodology as the pre-engagement baseline

€2.4M

Annualised waste eliminated

Inclusive of rework reduction, scrap reduction, and waiting time elimination

11wk

Full implementation timeline

From engagement start to signed-off control plan and client handover

0

Sustained process regressions at 6-month review

Follow-up audit conducted at 6 months confirmed all controls remained active and effective

"SNZ Sona didn't just fix a defect problem — they rebuilt how our operations think about quality. The Power BI dashboards mean our supervisors catch deviations in real-time, not at end-of-shift. The savings speak for themselves, but the capability they left behind is what we value most."
OD

Operations Director

Automotive Tier-2 Supplier, Lyon

Tools & Methods

Lean Six Sigma Black Belt methodology DMAIC framework Value Stream Mapping Power BI operational dashboards Gauge R&R studies Control plans

Next Step

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