“…This place of the PNPM represents the entry/exit point of the underlying system and thus, is actually not part of any service cycle. To avoid such unwanted cycles to be detected by the algorithm we examine the subgraph of G induced by the set of vertices |I − (Server 0, t 4 )(black) = 1 I + (Interm., t 4 )(black) = 1 I − (Server 0, t 4 )(red) = 1 I + (Interm., t 4 )(red) = 1 t 7 |I − (Travel 2, t 7 )(black) = 1 I + (Server 0, t 7 )(black) = 1 I − (Travel 2, t 7 )(black) = 1 I + (Server 0, t 7 )(red) = 1 t 10 |I − (Interm., t 10 )(black) = 1 I + (Rep., t 10 )(black) = 1 I − (Interm., t 10 )(red) = 1 I + (Rep., t 10 )(black) = 1 Figure 6 to enable the accurate representation of the underlying system's customer flow (Figure 7). Interm.…”