Global software development (GSD) involves teams working across different locations and time zones. Outsourcing in this context can take several forms, but the most complex, where multiple clients work with multiple vendors, is also the most difficult to manage and carries the highest risk of failure.

This paper introduces the Complex Outsourcing Relationships Management Model (CORMM), designed to help both clients and vendors better manage relationships in these challenging environments. The study follows a structured approach, starting with a systematic literature review, then proceeding to empirical validation, model development, and, finally, testing through real-world case studies.

The findings show that CORMM is effective in identifying key relationship management issues in complex outsourcing settings. Feedback from industry participants highlights CORMM’s practical value and usability. The model not only helps assess an organization’s current capabilities but also guides improvements by highlighting strengths and weaknesses.

Overall, CORMM offers a practical, evidence-based tool to support better collaboration and more successful outcomes in complex, multi-stakeholder software projects.