*2.6. Development of PEOS*

The PEOS is a hybrid heuristic algorithm combining the screening procedure of OOA and the heuristic algorithm SOS to automatically determine fault information in WDNs. The overall operational architecture and steps of PEOS are briefly given below (also in Figure 1):


The first stopping criterion is defined as the absolute difference between two successive optimal OFVs (in Equation (14)), which is always less than 10−<sup>4</sup> within four iterations. The second criterion for fault detection is the iteration reaching the specified maximum limit.

