Maintenance and Improvement of Product Quality

Following our acquisition of ISO 9001 certification for the Hachioji Plant and Tsuchiura Plant in January 1994, we built and have been operating the Tokyo Seimitsu QMS, a quality management system integrated across both plants. In line with transition to ISO 9001:2015, we obtained the certification in June 2017.

Under quality control managers at both plants, we engage in necessary PDCA activities and make continuous improvements to our Tokyo Seimitsu QMS to provide products and services that satisfy our customers.


Quality Improvement Activities through our QMS System Program

 To enhance performance and continuously improve our Quality Management System, we evaluate performance data for quality control items (quality management system program achievement rate, on-time delivery rate, nonconforming product rate, defective rate, complaint rate, etc.) at QC*5 meetings, and formulate and implement improvement measures. 

We input priority targets and activities requiring continuous improvement as quality targets for the next fiscal year, create quality target implementation plans and quality management system programs for each department and group, and formulate quality goal implementation plans.

Under the quality management system program, we confirm the results in Quality Subcommittee meetings held every three months, evaluate progress, and consider measures for improvement. Last fiscal year, we achieved 100% of our targets for 53 out of a total of 75 items, resulting in a 71% target achievement rate. For the remaining items, we clarify factors behind the nonachievement and feedback measures for improvement.

*5QC:Quality Control

Strengthening of Change Control

To prevent impacts on quality from changes in design and manufacturing processes, we perform change control for design, manufacturing, and services and work to continuously maintain quality.

Since establishing our Change Control Rules for high-level standard documents in 2017 and incorporating these into the lower-level standard documents of relevant divisions, we have reduced the risk of defects associated with change by conducting risk assessments of change control in line with these management standards.

We are now accumulating performance data from change control for use as a database concerning similar changes, and are improving the environment to enable speedier and more efficient change control.  Regarding the reduction of complaints associated with change control, from 2018 we have set an effectiveness index for change control as a KPI*⁶, with 0.5% or less as our target value.

Change control effectiveness ratio (%) = 
Number of complaints / Number of change controls implemented x 100%

Our change control effectiveness ratio in fiscal year 2020 was 0.38%, achieving our target value.

*6KPI:Key Performance Indicators

Activities for Supplier Quality Improvement

Ensuring quality in procured components is essential for achieving stable and reliable product quality. With our suppliers as key partners, we will carry out our social responsibilities throughout the supply chain. We distribute the document "Quality Systems and Environmental Systems Expected of Partner Companies" to suppliers and work to maintain and improve the quality of the products we procure.

We manage quality defects in procured products using Defective Product Notices, and work with suppliers to investigate root causes and prevent recurrence of the issue. Depending on the degree of defect, we conduct audits and cooperate with the suppliers in improving quality.

In fiscal year 2020, we were unable to conduct quality audits because of the COVID-19 pandemic. Accordingly, we selected 16 suppliers based on delivery record and quality status, summarized analyses of the causes of issues that occurred along with recurrence prevention measures, and offered quality guidance to the suppliers to improve quality.

We plan to resume quality audits in fiscal year 2021.

Initiatives for Customer Satisfaction

Tokyo Seimitsu conducts questionnaire-based surveys of customers who use our products. We use their opinions to improve and enhance our products and services, and work to raise customer satisfaction.

Improvement Activities Based on Customer Satisfaction Surveys
(Initiative by the Semiconductor Company)

Every year, we conduct a customer satisfaction questionnaire survey concerning our products, and aggregate and analyze the results.

Comparing these with the results of the fiscal year 2019 survey, we have affirmed improvement in many items. Graphs of semiconductor manufacturing equipment probers and cutting blades, based on the results of the current fiscal year's questionnaire, are shown as examples.

FY2020 questionnaire findings (Equipment : Probers)
FY2020 questionnaire findings (Equipment : Probers)
FY2020 questionnaire findings (Cutting tools : blades)
FY2020 questionnaire findings (Cutting tools : blades)

In addition to customer visits, the web-based system that we introduced in fiscal year 2018 has become widely used, and our fiscal year 2020 survey received 110% of the responses received in the previous year.

We will continue efforts to reflect the opinions of our customers in the improvement of customer satisfaction.

Improvement Activities Based on Customer Satisfaction Surveys
(Initiative by the Metrology Company)


We use a customer satisfaction questionnaire to survey customers one year after purchasing measurement products, and aggregate and analyze the survey results.

Our goal is a customer satisfaction score of 3.7, a target that we met in fiscal year 2020 with a score of 3.97. Aiming for further improvement, we respond to all individual customers' comments in the customer satisfaction questionnaire.


In addition to this questionnaire, in July 2019 we began using a NPS® (Net Promoter Score) questionnaire. We analyze the results of this questionnaire to improve customer loyalty.