HumanCentric Technologies and Think Design have merged their operations. But the two firms are hardly strangers either to each other or clients.

HumanCentric, which focuses on how humans will be affected by product design and services, and Think Design, which is an industrial design firm, have been working on a number of mutual projects over the past year.

The deal, which makes Think Design part of HumanCentric, “truly is a merger,” said Dana Dorroh, director of business development for HumanCentric. “We are taking over the operation, the staff, the facility — every piece.”

Terms were not disclosed.

The two firms mutually established a Product Design Center six months ago after working together on a number of other projects.

“Joe and Barry were calling on each other, talking to the same clients, making joint sales calls and joint responses,” Dorroh said, referring to Barry Beith, president of HCT, and Joseph Jasinski, president of Think Design.

Together, the two companies already have won a number of deals, including projects with Whirlpool, Abbott Labs, Newell Rubbermaid, Amersham Health and Ohmeda Medical.

Through the Product Design Center, Dorroh said, clients can order a turnkey product design.

“The Product Design Center validate a number of ideas,” she explained. “We would get requests for services that spanned what both companies were doing.”

The five members of Think Design will join HumanCentric, and Jasinski will be director of design. The Think Design Product Center will be located in Raleigh.

HumanCentric now has 35 employees.

“This is an important milestone,” Beith said in a statement. “It extends our capabilities by supporting product development projects from conceptual ideation to market realization.”