Automagical bottleneck detection is the holy grail of performance testing. Depending upon what you setup for monitoring and how you are able to cross correlate with your observed results you can derive insight onto the source of the bottleneck, i.e., a long response time combined with high disk activity on the database server + high table scans + high number of records transferred to client likely indicates an unoptimized query missing and index and (perhaps) returning more data than is absolutely necessary to satisfy the client need.
Performance analysis is a field which is particularly well suited to expert systems development for inclusion of rules to analysis sets for candidates for bottlenecks