1981 April	Established Nikken Sogyo Co., Ltd.(Nikken Total Sourcing Inc.) in Kamata, Ota-ku, Tokyo as an in-plant outsourcing company.
1989 May	Established Ability Nikken Co., Ltd. to dispatch clerical workers.
1994 November	Inaugurated the new headquarters building in Nishikamata, Ota-ku, Tokyo.
1996 December	Acquired shares of Altekna Co., Ltd., which became an engineering outsourcing affiliate.
1999 October	Obtained a license for general worker dispatch service and launched a temporary staffing service.
2001 April	Established Nihon Tact Co., Ltd. to provide outsourcing services for manufacturers.
2002 December	Obtained a license for employment placement service and launched a recruitment service.
2003	Established Nishio Skill Center.
2004 March	Launched a worker dispatch service for manufacturers after the Revised Worker Dispatch Law was instituted.
May	Established Nikken Kankyo Service Co., Ltd. (which obtained authorization in November 2004 to become a special subsidiary promoting the employment of workers with disabilities).
October	Established Takasaki Techno Center (recognized as an official vocational training facility).
2005 March	Established Higashi Hiroshima Techno Center.(recognized as an official vocational training facility).
October	Established Sendai Techno Center. (recognized as an official vocational training facility).
2006 July	Obtained Privacy Mark certification.
2007 April	Established Nikken Sogyo Health Insurance society (Nikken Group Health Insurance Society).
2008 March	Acquired shares of Sanwa Group companies (Sanwa Co., Ltd., Intertechno Co., Ltd. and Techno Center Co., Ltd.), which became engineering staffing affiliates.
2011 April	Acquired Eco-Action 21 certification for environmental management initiatives.
2014 August	Established a joint venture company, Nikken (Thailand) Co., Ltd., to provide staffing/outsourcing services in Thailand.
	Entered into capital partnership with Staffers Recruitment Consultants Co., Ltd. in Thailand.
2015 April	Established Kumamoto Techno Center.(recognized as an official vocational training facility).
May	Established Nagoya CAD Training room.
October	Changed the corporate name to Nikken Total Sourcing Inc.
November	Established Hokuriku Techno Center.(recognized as an official vocational training facility).
2017 January	Nikken (Thailand) Co.,Ltd. made World Asia Solutions Co., Ltd. its subsidiary company.
May	Established Tokyo CAD Training room.
September	Established Nagoya Techno Center.(recognized as an official vocational training facility).
2018 March	Established Kansai Techno Center.(recognized as an official vocational training facility).
April	Established Tokyo Technical Center.
June	Established Osaka Technical Center.
	Acquired shares of Arum Holdings Co., Ltd., Arum Medical Support Co., Ltd.
2018 December	Selected as a "Companies Driving Regional Growth" by the Ministry of Economy, Trade and Industry.
2021 April	Established Kitakami Techno Center.
May	Established Sendai Skill Center,Keihan Skill Center
2022 February	Established Kanto Techno Center.
March	Established Yokkaichi Techno Center.
June	Established R&D Training Center, Nagoya Technical Center.
2023 April	Established Saitama Techno Center.