In order to integrate disciplines, it's imperative that people working on cross-functional teams understand some intricacies of other disciplines. Such issues are related to timing, cost, risk and the effort required.
Proper cross-training – so that the team members better understand the processes of the other specialists – takes time. The idea of multiple people dealing with the same issues is rife with redundancies. This can slow things down and add to time spent on a job for which a client doesn’t want to pay. Significant problems can arise if time is mismanaged.
On the other hand, some of our freshest ideas come from the specialists who are not primarily responsible for a task. Much myopia and tunnel vision are eliminated when eyes from different disciplines look at a challenge. We've found that art directors can have bright ideas about financial matters. Media people edit headlines, etc. One of our first-year public relations specialists wanted to try his hand at advertising writing. He wrote a radio commercial for a national media buy that was chosen over the work of our most senior writers. And because his success was their success, they were happy see this young man's work chosen for production.