Sumitomo Wiring Systems, Ltd. Business Report FY ended Mar. 2016

Recent Years

Aluminum Wiring Harnesses

-The Company aims to increase the sales of lightweight aluminum wiring harnesses to 10% of its entire harness sales by the fiscal year to end in March 2018 (FY 2017). The aluminum wiring harness offers an approximately 50% reduction in weight compared to wiring harness made of copper wires. The Company began supplying its aluminum wiring harnesses to Toyota Motor Corporation in 2010. Initially, the aluminum wiring harnesses showed disadvantages in vibration resistance and corrosion resistance compared to copper-made products. The aluminum wiring harness now offers increased durability after many improvements have been made. Sumitomo Electric Industries, Ltd., the parent company of Sumitomo Wiring Systems, has also decided to increase the monthly production capacity of aluminum wires at its Thai plant to 300 tons, which is about five times the present capacity, by FY 2016. Sumitomo Wiring Systems will propose its product to manufacturers in Japan, the U.S. and Europe to achieve its sales target. (From an article in the Nikkan Jidosha Shimbun on November 25, 2014)

Recent Development Outside Japan


-Sumidenso Paraguay S.R.L., the Company's subsidiary in Paraguay, officially began its production operations on September 8, 2015.

-The Company will set up a new plant in Paraguay in the fiscal year ending in March 2016 (FY2015). The new plant will serve as a production base to supply wiring harnesses to Japanese and European automakers in Brazil. Labor costs in Brazil are relatively higher than those in other South American countries. Opening a production base in the country neighboring Brazil will allow the Company to keep its production costs lower and improve its cost competitiveness. This will be Sumitomo Wiring Systems' first plant in Paraguay and the sixth in South America. The plant will start operations in the first half of FY 2015. Its initial workforce is around 1,000 but the number will be expanded to around 4,000 in the medium term. (From an article in the Nikkan Jidosha Shimbun on November 11, 2014)


-In October 2014, Sumitomo Electric Industries, Ltd. announced a JPY 7.3 billion investment project for its wholly owned subsidiary, SEI Thai Electric Conductor Co., Ltd., which manufactures aluminum wires and aluminum rod materials in Thailand. The Rayong-based subsidiary will install an aluminum casting and rolling machine in order to establish an integrated production system for automotive aluminum wires. The products will be supplied directly to Sumitomo Wiring Systems' wiring harness plant in Thailand, which is expected to improve the group's overall production efficiency. SEI Thai Electric Conductor also plans to increase its aluminum wire production capacity to meet growing demand from Japanese automakers. (From an article in the Nikkan Jidosha Shimbun on October 20, 2014)

R&D Facilities

Name Location
Utsunomiya Engineering Center Tochigi Pref., Japan
Hino Engineering Center Tokyo, Japan
Atsugi Engineering Center Kanagawa Pref., Japan
Hamamatsu Engineering Center Shizuoka Pref., Japan
Susono Engineering Center Shizuoka Pref., Japan
Toyota Development & Engineering Center Aichi Pref., Japan
Okazaki Engineering Center Aichi Pref., Japan
Kariya Engineering Center Aichi Pref., Japan
Matsusaka Engineering Center Mie Pref., Japan
Kanazawa Engineering Center Ishikawa Pref., Japan
Osaka Engineering Center Osaka, Japan
Hiroshima Engineering Center Hiroshima Pref., Japan
Kyushu Engineering Center Fukuoka Pref., Japan
AutoNetworks Technologies, Ltd. Mie Pref., Japan
SEWS Mexico S.A. de C.V. Aguascalientes, Mexico
SEI ANTech-Europe GmbH Mainz-Kastel, Germany
SUMI REMA EV Solutions GmbH Bonn, Germany
SEWS-CABIND S.p.A. Collegno, Italy
SEWS-STC Co., Ltd. Shanghai, China
Kaifeng Rijin Wiring Systems Co., Ltd. Henan, China
Sumidenso Automotive Technologies Asia Corporation St. Clark Freeport Zone, Philippines
SEWS-Asia Technical Center Bangkok, Thailand

R&D Structure

Wire harnesses / In-vehicle electronic equipments
-R&D activities are mainly conducted at AutoNetworks Technologies, Ltd., which is jointly owned by the Company and Sumitomo Electric Industries, Ltd. R&D activities are mainly focused on developing new products meeting safety, comfort and environmental needs.

-Wire harnesses:

  • The Company is building harness architectures that can be mounted in next-generation vehicles' onboard systems, conducting R&D activities on elemental technologies needed to meet this need.
  • Also, in order to reduce vehicle weight and be environmental friendly, the Company is developing lighter weight harnesses. It has succeeded in this area, developing and starting mass-production of harnesses using aluminum, which is lighter in weight than copper. >>>Wiring harnesses based on high-strength alminum wires at 2016 JSAE exhibition
  • Moreover, the Company is continuing its R&D activities on high-voltage harnesses, connectors, battery wiring modules and so on for the growing EV/HEV sector. >>>High voltage cable for HEV at 2016 JSAE exhibition

-In-vehicle electronics devices:

  • The Company is now developing electronics devices such as PDs (power distributors) and next-generation in-vehicle LAN (Local Area Network) units in order to respond to the rapid advances taking place in IT. The Company is also launching systems with advanced features and/or networking capabilities.

Product Development

-In October 2016, The Company announced that it has constructed an experiment building, which has a radio wave darkroom with a chassis dynamometer, within the premises of its Suzuka Plant in Mie Prefecture, Japan. JPY 1.9 billion was invested in the new building, which has a total floor area of 1,981 square meters. The new test facilities will allow the company to measure the effect of noise sources on communication and electronic devices in an actual vehicle running environment. (From a press release on October 3, 2016)