Peak demand has an important role in water distribution system design because it is associated with one of the most burdensome operating scenarios in a network. For this reason, peak demand has been widely discussed over the last century. Traditionally, peak demand assessment has focused on determining the peak demand coefficient or peak factor, which is defined as the ratio between the maximum and the mean daily flow. Authors like Harmon (1918), Babbitt (1928, Metcalf and Eddy (1935), or Johnson (1942) (among others) proposed expressions that provide the peak factor at sewer systems based on the size of the population. These empirical equations set up the basis for peak demand analysis at water supply systems, although they address the problem from a deterministic point of view.Water demand is nowadays recognized as one of the main random factors that condition flow variability (Magini et al., 2008). The development of stochastic demand models that simulate the complex pulsed nature of water demands has motivated the shift toward probabilistic (rather than deterministic) demand analysis (Vertommen et al., 2015), also for peak demand assessment. According to the literature review presented by Creaco, Blokker, and Buchberger (2017), stochastic demand models can be broadly classified as: (a) household-based models, which adjust statistical models based on flow measurements at monitored households, like the Poisson Rectangular Pulse (PRP) model originally presented by Buchberger and Wu (1995), and (b) end-use models, which compute household consumption by aggregating the contribution of each end-use or microcomponent (e.g., taps, showers, washing machines) according to survey-based data. Zhang et al. (2005) and Creaco et al. ( 2018) have already applied PRP-like models to assess peak demands. Zhang et al. (2005) proposed a theoretical explanation for peaking factors by combining a PRP model with extreme value theory. Balacco et al. (2017) adapted this approach to a case study in Italy, comparing it with traditional formulas and real measurements. On the other hand, SIMDEUM (SIMulation of water Demands, an End-Use Model) is the reference microcomponent model at present (Creaco, Blokker, & Buchberger, 2017), and it has also been used to compute accurate estimates of peak demands (Blokker et al., 2012).Addressing peak demand assessment probabilistically is not the only current challenge. The temporal and spatial resolution effect on peak factors is being discussed as well. As pointed out by Tricarico et al. (2007), assuming a time interval of one hour (traditional temporal framework for peak assessment) may result in an underestimation of peak demand, because major peaks could take place within the hour. On the contrary, using very fine time scales (e.g., 1 s) is excessive considering that per second variations are not expected to be decisive in order