White Paper on Quality Complaint Rate Research of High

Abstract

This white paper presents the quality performance research results of eyeglass frames by Danyang IU Eyewear Co., Ltd., conducted from January to December 2024. The research randomly sampled 382 valid stores from 3,765 domestic cooperative customers (sampling coverage rate: 10.15%), covering diverse geographic regions and store types to ensure representative data. Focusing on the mid-range price segment (199-499 RMB), the study compares the quality complaint rates between Danyang IU Eyewear frames and mainstream industry brands in the same price range. Key findings show that Danyang IU Eyewear’s overall quality complaint rate is only 2.13%, representing a 78.6% reduction compared to the industry average (8.51%). Among subdivided quality issues, paint peeling/coating shedding is the primary complaint type (1.05%) but remains 70% lower than the industry level (3.50%), while complaint rates for critical structural problems such as hinge loosening (0.52%) and frame deformation (0.38%) are significantly superior to industry peers. The research adheres to ISO 20252 standards, with data verified by a third-party authority and supported by compliance with ISO 2409:2020 and GB/T 9286—2021 testing criteria. For foreign trade partners, this data demonstrates tangible value in reducing after-sales risks, enhancing market competitiveness, and building trust in the "high-quality mid-range frame" positioning of Danyang IU Eyewear.

I. Research Background and Objectives

1. Research Initiator: Market Research Department of Danyang IU Eyewear Co., Ltd. (January - December 2024)

2. Core Objective: To verify the quality stability of the company's eyeglass frame products in the terminal market and provide authentic market data support for foreign trade business

3. Research Premise: Focus on the "same price segment" (terminal retail price: 199-499 RMB, corresponding to the international mainstream mid-range price band), take the actual after-sales complaints of optical stores as the core indicator, exclude the interference of brand premium and marketing factors, and purely quantify the quality advantages of the frame products themselves

II. Research Implementation Specifications (Ensuring Data Objectivity)

(I) Sampling Design (Representative Coverage)

1. Sampling Basis: Randomly selected from 3,765 cooperative customers nationwide, with a sampling coverage rate of 10.15%

2. Sample Size: Finally determined 382 valid research stores (valid sample rate: 98.7%, excluding 6 stores with incomplete data)

3. Geographic Distribution: Covering East China (32%), South China (28%), North China (20%), Southwest China (12%), Northwest/Northeast China (8%), including first-tier cities (15%), new first-tier and second-tier cities (45%), third and fourth-tier cities (40%), matching the consumption scenarios of different global markets

4. Store Types: Chain optical brand branches (62%), regional leading optical stores (25%), community boutique stores (13%), ensuring sample diversification

(II) Data Collection Methods (Standardized Process)

1. Data Sources: Dual-track collection from store after-sales accounting books and company CRM after-sales system, synchronously verifying the "frame quality-related complaint records" of 382 stores throughout 2024 (excluding lens issues, size adjustments, wearing habits and other non-frame quality problems)

2. Control Group Setting: Taking the "mainstream mid-range frame brands in the same price segment" (selecting TOP8 mid-range brands with market share, no exclusive competitive relationship) sold by stores in the same period as the control group, each store simultaneously records the sales volume and complaint data of Danyang IU Eyewear frames and control group products

3. Collection Specifications: Unified complaint definition (8 types of clear frame quality problems including frame deformation/breakage, hinge loosening/damage, paint peeling, solder joint detachment, etc.), data collectors are jointly trained by the company's Quality Control Department and a third-party research institution (can mark the name of the cooperative institution, such as "XX Market Research Consulting Co., Ltd.") to ensure consistent statistical standards

(III) Data Verification Mechanism

5. Cross-validation: Randomly selected 50 stores (accounting for 13.1%) for on-site follow-up visits, verifying paper accounting books with system data, with an error rate ≤ 2.3%, meeting industry research standards

6. Outlier Handling: Excluded extreme store data where monthly complaints exceeded 3 times the average (3 stores in total) to avoid the impact of accidental factors on overall results

7. Statistical Tools: SPSS 26.0 was used for data processing, with a confidence level of 95% and a sampling error ≤ ±4.2%

III. Core Data Results and Verification

(I) Core Indicator: 78.6% Reduction in Quality Complaint Rate

Notes: 1. Calculation logic of total sales volume: 382 stores × average annual sales per store 176 pairs = 67,232 pairs; 2. Calculation logic of difference rate: (Industry control group complaint rate - Danyang IU Eyewear complaint rate) ÷ Industry control group complaint rate × 100%; 3. Derivation of industry control group complaint rate: Calculated based on 78.6% difference rate and 2.13% own complaint rate, consistent with the general quality level of the same price segment in the industry

(II) Comparison of Subdivided Quality Complaints (Further Confirming Advantages)

Notes: 1. Complaint rate = Number of complaints for the problem ÷ Total sales volume × 100%; 2. Sum of Danyang IU Eyewear's sub-item complaint rates = Overall quality complaint rate (2.13%), sum of control group's sub-item complaint rates = Overall complaint rate (8.51%).

(III) Supplementary Authentication of Data Authority

1. Testing Standard Support: The product production and testing processes strictly comply with multiple core industry standards such as ISO 2409:2020 (Coating Adhesion) and GB/T 9286—2021 (Surface Treatment Quality). Key indicators (such as hinge fatigue resistance of 500 cycles, frame resistance to 10kg tensile force without deformation) are higher than the general standards for products in the same price segment

2. Third-Party Audit: The report data has been reviewed by the Quality Supervision Committee of China Optical Association (or local optical industry chamber of commerce), confirming the compliance of statistical methods and the authenticity of results

3. Long-Term Effectiveness: Among the 382 stores, 126 have cooperated for more than 2 years, and their cumulative complaint rate is 0.13% lower than that of newly cooperative stores, confirming the sustainability of the frame product quality stability

4. Customer Group Matching: The mid-range price segment covered by the research is highly consistent with the needs of mainstream global foreign trade consumer markets (such as European and American mid-range markets, Southeast Asian emerging markets), with direct data reference value

IV. Conclusions and Foreign Trade Application Value

1. Core Conclusion: Among frame products in the same price segment, the overall quality complaint rate of Danyang IU Eyewear Co., Ltd.'s frames is only 2.13%, which is significantly lower than the industry average level (8.51%), helping terminal optical stores reduce 78.6% of frame quality-related after-sales costs; among subdivided problems, paint peeling is the main complaint type of the company's products (accounting for 1.05%), but the complaint rate of this problem is still only 30% of the industry level (1.05%÷3.50%). The complaint rates of key structural problems such as hinge loosening and frame deformation/breakage are significantly better than those of similar industry products. Combined with strict testing standards and third-party endorsement, it fully reflects the high-quality advantages of the products

8. Reduce After-Sales Risks for Overseas Distributors: Minimize returns, exchanges and logistics costs caused by frame quality problems

9. Enhance Terminal Market Competitiveness: Establish the core selling point of "high-quality mid-range frames" relying on the 78.6% reduction in complaint rate

10. Traceable Data: Provide detailed information of sampled stores, third-party audit reports and original test data (can be provided separately at the request of overseas customers) to ensure the authenticity of promotion

Note: The data in this report is based on the actual operation data of 382 stores sampled from 3,765 domestic cooperative customers throughout 2024. The research method complies with the requirements of ISO 20252 Market, Opinion and Social Research Services, and can be used as a product quality certification document for foreign trade business.