Performance analyser or PAL stores data which captures the information which is necessary to identify these inefficiencies or excessive use of resources in your application. You can review a detailed article about the same here.
You should also be able to monitor the health of the system from SMA. Moreover, OOTB PegaRULES-ALERT logs provide a detailed list of the alert and exceptions logged in an application.
You can identify the bottlenecks in your application using the frequency of a particular alert and the threshold it has crossed.