"Most of what you read about silo-busting talks about eliminating hierarchy and flattening the organization, but there is nothing hierarchical about silos. Organizations don’t establish silos—or boxes on org charts—with the goal of destroying trust, stifling communication and fostering complacency. They do it to allocate resources efficiently."
Read the full article to find out why silos have nothing to do with the problems silo-busting is designed to achieve and why it has everything to do with culture.
I found this article incredibly helpful in addressing the "culture" change required to address silos. It may take more than organizing cross-functional after work events or onsite mixers to change the culture. And, there is value in recognizing when a silo can be used for a targeted communciations need.