“…Some studies in the VRP with multiple trips and time windows (VRPMTTW) were Suprayogi [17], Suprayogi and Imawati [18], Suprayogi et al [19], Azi et al [20], Suprayogi et al [21], Cattaruzza et al [22], Hernandez et al [23], and Hernandez et al [24]. Ong and Suprayogi [25] investigated the VPTMTTW in context of backhaul operation. The VRP with time windows and simultaneous delivery-pickup (VRPT-WSDP) was studied, for example, by Mingyong and Erbao [26], Fan [27], Wang and Chen [28], Liu et al [29], Avci and Topaloglu [30], and Wang et al [31].…”