Background: Due to the fast-growing economy and in order to stay relevant in the actual competitive markets, companies need to put more emphasis on innovation. Hence, developing and introducing new products to the markets on time is still a challenge and requires a certain among of efforts and interactions between different cross-functional teams. Accordingly, the studies about internal collaboration in new product development projects are still limited and have remained mostly quantitative. Regarding this, it is crucial to understand how teams can build collaboration and secure the time to market for new products.

Purpose: The purpose of this research is to contribute to the literature regarding internal collaboration within new product development projects. To address answers to the purpose, the following question was formulated. "How do cross-functional teams build internal collaboration to ensure delivery precision of time following the stage-gate model in new product development projects?".

Method: First, literature was reviewed to provide a foundation for the theoretical framework. Second, a single-case study at Husqvarna Group AB was conducted, and the main empirical findings were taken from interviews, observations, and documents. Then, to interpret the collected data, the grounded theory method was used. Finally, the theoretical framework and the findings were analyzed and discussed to answer the research question.

Conclusion: The empirical findings revealed different practices that can be related to existing factors of internal collaboration. Also, it presents a new conceptual model that shows how cross-functional teams build internal collaboration through these practices following the stage-gate model in new product development projects to ensure delivery precision of time. Furthermore, this research raises special attention to the pre-study as a crucial phase where teams start to build collaboration avoiding possible delays in the projects.