Knowledge management

How is knowledge managed in your organization? Does your organization use any knowledge management tools, such as enterprise social networking tools, collaboration tools, to promote communication and proactively manage knowledge? What works well? What actually creates barriers to knowledge exchange in your organization? In addition to the knowledge management tools, does your organization have any rules, incentives, etc. in place to encourage knowledge sharing and exchange in workplace? Which is more important, the tool or the policy, to the success of knowledge management in your opinion?