There are a few challenges when adopting SDDC. Many technical aspects are custom built, and require expertise, however, the main challenges are primarily human in nature.
A primary hurdle is in gaining cross-functional agreement between disparate departments. The problem is siloed data, process and policies. Each department has their own frameworks and models for operating. But because SDDC is a holistic system, which will eliminate those siloes, caution must be taken when introducing the idea of breaking silos down, or what could be interpreted as encroachment into departmental territories.
The following challenge, after department buy-in is strong, is switching environments and the subsequent planning, implementation, and accounting for downtime. The safe approach, and one that cloud-based SDDC allows when moving to modernized systems is to do it in stages. It is not necessary to migrate an entire system in one shot.
The final challenge is in instituting new processes and workflows. Even when buy-in is high, training and feedback must still happen. Enthusiastic people may achieve their training faster. But it must be nuanced with the idea that SDDC processes and workflows are different from what was used before.