Expertise can be surprisingly difficult to find, even in institutions that have spent millions to attract and retain world-class experts. Take the experience of one manager at a biotechnology company.

"Early in the project, it needed someone with deep technical knowledge of a particular protein. We spent weeks looking for an expert—calling HR, asking around the office, scanning personnel records. Finally, we concluded the expert didn’t exist. Three days later, I’m in an elevator complaining about this to a colleague, when the woman next to me turns and says, ’I wrote my doctoral thesis on that protein. What do you need to know?’"

Such inefficiency and reliance on chance would normally be unthinkable for corporate resources. Project managers don’t find cash lying around in elevators. Store managers don’t idly speculate on the whereabouts of their inventory. IT managers don’t spend weeks rummaging through offices for spare computer terminals. Companies, after all, follow well-established processes to connect valuable resources (cash, inventory, equipment) with the people who need them.

The same can’t always be said of expertise. In some instances a formal process hasn’t been necessary. For companies with small, simple organizational structures, informal social networks have been reasonably effective at...