One of the biggest challenges of companies developing new solutions is how to properly manage the different relationships with external partners, especially in the case of Product-Service Systems (PSS). Developing a PSS requires for Original Equipment Manufacturers (OEM) to rethink the organization and roles of the different stakeholders regarding the characteristics of such environments. This paper aims to introduce a methodology to build a framework for inter-enterprise collaboration performance assessment and its corresponding Key Performance Indicators (KPIs). An extensive list of KPIs is established from key factors of collaboration performance and organizational characteristics in PSS context. Finally, further steps of the methodology are discussed where fuzzy techniques are used.