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Sumitomo Wiring Systems' Manufacturing

Quality Control

Quality Management
We want to live up to our customers’ trust by ensuring “Globally Common Quality with Product Appeal No. 1”

SWS aims to achieve "worldwide uniform and product appeal No. 1 quality" so that customer-satisfying products can be supplied in whatever nation they are produced. We will introduce the quality management activities we have focused on recently.

Each line strives to eliminate all defects

HAI-Q line

Production lines throughout the world are striving to increase the number of straight days without suffering any defects. More than 1,200 production lines have achieved 10 straight defect-free days.When defective products are found, the line is immediately stopped and all operators work together to identify the causes.

We promote quality control activities to eliminate all defects in each of our manufacturing process. Each factory determines which line to focus on elimination of all defects, makes an application, and then starts the required activities. A line that operates for 10 straight days with no defects qualifies as an HAI-Q line, including “absolute line,” “outstanding quality line” or “QA best line.” After that, the time is extended to 30 days, 60 days, and even 100 days as we strive to reach a longer no defect state. Currently, more than 1,200 lines around the world have qualified.

A defect will spoil all previous efforts made on a qualified line, which increases the focus of every operator working on the line and helps all operators work together. When problems occur in the manufacturing process, the line is immediately stopped to identify the causes and solve them. Achieving a record of long straight no defect days is very meaningful, but stopping a line immediately after a problem occurs is also significant. An immediate search for the root causes with no postponement will bring effective countermeasures.

Mechanisms and control to ensure quality on the shop floor with changes or modifications

Scenes from a PK evaluation

Unusual changes, such as “One of the operators is absent” or “New materials are being used,” often lead to problems. So, we’ve introduced the “Changes Board” to clearly indicate the changes or modifications of the day and help everyone adapt to the new conditions.

Our factories deal with a broad range of parts. If the factories aren’t in order, operators may inadvertently use the wrong parts or dirt may stick to products. To prevent such errors, we do “PK” activities to check that our operations are correctly done. These activities are based on the often-heard 5Ss: Sorting, Systematizing, Sweeping, Sanitizing, and Self-discipline.

We start with the basics: for example, sweeping the factory and the equipment. Then, we strictly check that operations or inspections conform to the criteria, including control standards or systems, which determine proper levels. This enables us to keep the same, high quality and provide products that have met the proper levels.

Daily concerns on the manufacturing floor are changes or modifications: “One of the line operators is absent,” “New materials are being used,” or “The designs have been changed.” Unusual changes such as these often lead to quality problems. The challenge is how to avoid the problems, so we’ve introduced the “Changes Board.” We use the board to clearly indicate the changes or modifications of the day, in people, materials, or operation methods, and to help everyone learn their contents. Different people work with different materials in our workplace. We’ve built a mechanism that can ensure quality even when situations change everyday, every hour, and even every minute. Preliminary preparation methods and post-check methods have been enhanced to manage variation and changes.

Improved quality through various activities, such as the HAI-Q (HArness Innovation Project Quality) Activity, practical staff training and QC circle activities

Company-wide meeting of QC Circle

We hold briefing sessions in “QC Circle Activities,” quality improvement activities in workplaces, to share the details of the activities. Different approaches, such as “Quality HIT” and “S Brainstorming,” are always promoted to improve quality.

SWS provides instructions to solve quality problems that have occurred at manufacturing sites located throughout the world.
The HAI-Q Activity system has been established, where headquarters provides support to solve quality problems of manufacturing lines with high in-process defect ratio.
When the personnel involved in the relevant manufacturing line are registered in the HAI-Q Activity system, training is conducted for them to acquire problem solution techniques. Activity themes are then narrowed down, problems are figured out through observation of facts, and discussions are carried out to identify the true causes using the Why-Why Analysis technique.
In most manufacturing lines, in-process defects are reduced by half within five months after the manufacturing process is improved based on the solutions discussed in the regular HAI-Q Activity. Implementing quality improvement activities utilizing the HAI-Q Activity system improves the quality management level of global manufacturing sites.

A practical staff training system has also been established to cultivate the problem solving abilities of the staff. Teams are organized with four trainees per team. After learning the problem solution method, teams are assigned to manufacturing sites to work on technical problem solutions for three months.
A variety of technical problems have often been solved by working on a team to figure out the facts in question and identify the true causes based on these facts.

Different efforts decrease the number of complaints and the complaint index every year

The part of the evaluation from a customer

As a professional manufacturer, we’re committed to providing products that live up to our customers’ expectations. This has earned us a solid reputation with our customers.

The number of complaints has decreased due to the various approaches and activities we have taken. We are also awarded the Quality Prize from many customers every year.
Our customers’ requirements are becoming more complicated, with sophisticated technologies and diversified evaluation criteria. As a professional manufacturer, we’re committed to providing products that live up to our customers’ trust or those with “Product Appeal No. 1 Quality.”

“Assurance of Each Process” activities focus on no defects

We’re creating defect-free processes, or at the very least which find any defects as soon as they occur, we call this “Assurance of Each Process” activities. We believe the activities should be developed not only on the manufacturing floor but also throughout all manufacturing processes, including product design.

In addition to taking measures after a defect occurrence, we’re creating processes that cause no defects or that find defects and prevent them from reaching the following processes. Sumitomo Wiring Systems calls the activities “Assurance of Each Process” activities.

We have started “Assurance of Each Process” activities on critical or new manufacturing processes, focusing on no defects and targeting 100% product assurance. For a new process, we apply the requirements for accepted products to product design, equipment design, and process control methods to avoid defects. On the manufacturing floor, we put training and control in place to help everyone observe the requirements.

For an existing process where defects may occur even if the standards are observed, we consider measures that allow the defects to be reliably found in the process and measures that prevent the defects through improvements in equipment and product design. “Assurance of Each Process” activities are implemented with close cooperation between three departments: Design, Production Engineering, and Manufacturing.

We repeatedly examine the requirements for accepted products on model lines in Japan and provide the results to our manufacturing bases around the world. Sumitomo Wiring Systems believes that quality is built not only on the manufacturing floor but also through all manufacturing processes, including product and process design.

Basic Concept of “Assurance of Each Process” Activities

‘Quality Training Room’ with display of past problems

image:Quality Training Room’ with display of past problems

Panels summarizing causes and measures for critical quality problems that occurred in the past, management method of important processes etc. are displayed in the Quality Training Room. We will use this room for quality training according to rank in the organization.

The Quality Training Room displays ‘causes and measures for past critical quality problems’, ‘principle of important processes and management method’, ‘latest problems’ and ‘companywide quality activities’. In addition to the panels, related samples and materials are displayed to facilitate understanding of the details.

Holding reporting session titled ‘Quality Forum’

image:Holding reporting session titled ‘Quality Forum’

Under the Quality Month theme ‘go back to basics of quality and discover knowledge of pioneers’, we held a session to report ‘quality improvement activities’ and ‘measures implemented for problems’ with display of panels.

Approximately 150 people participated in the session to report quality improvement activities, and the session was broadcasted to 35 bases in Japan and overseas, including seven Asian bases. Panels describing problems were displayed at the back of the session room to produce an interactive display.