Collaborative product design processes of industrial design and engineering design in consumer product companies

•Four types of collaborative product design processes exist in consumer product domain.•The types are determined by the approaches adopted before the detail design phase.•The four types of processes are used for different purposes in different contexts.•Industrial designers' contribution is dominant in the concept design phase.•Engineering designers' major role comes mainly after concept design phase.

This study aims to elucidate how industrial designers and engineering designers collaborate, and how such an alliance reflects in the design process. We conducted in-depth interviews about actual product design projects with 34 industrial and engineering designers from six consumer product manufacturers. We firstly identified individual design processes from the interview data. Secondly, we then compared and merged the design processes into collaborative processes using a mosaic method. We finally simplified the collaborative processes to create representative process models. As a result, we discovered four types of typical collaborative product design processes and their characteristics - Type 1: ID-led Concept-driven Process, Type 2: ID-led Combined Outside-inside Process, Type 3: ED-led Inside-first Process, and Type 4: ID&ED Synergetic Process.