Many executives invest considerable resources in restructuring their companies, drawing and redrawing organizational charts only to be disappointed by the results. That's because much of the real work of companies happens despite the formal organization. Often what needs attention is the informal organization, the networks of relationships that employees form across functions and divisions to accomplish tasks fast. These informal networks can cut through formal reporting procedures to jump start stalled initiatives and meet extraordinary deadlines. But informal networks can just as easily sabotage companies' best laid plans by blocking communication and fomenting opposition to change unless managers know how to identify and direct them.…