The development and installation of new or upgraded process technology in production plants may require strong collaboration among the process firm and the equipment suppliers. Such collaborations however entail both advantages and disadvantages to the partners. By means of an explorative case study in two process firms, we aim to shed light on the problems and opportunities arising from such collaborative efforts. By combining literature on open innovation, collaborative development and complex procurement, we address the questions of why, when and how such collaboration should be organized and managed. As such, the article contributes to management practice by helping process firms and equipment suppliers to better reap the benefits arising from joint collaborative efforts, while simultaneously avoiding the risks. Collaborative development was found important due both cost and competence reasons, especially during the early design stages and start-up activities. While collaborative performance was chiefly based on careful partner selection coupled with incentives and joint objectives.