This model allows studying how two main entities of a ski resort are connected to and influenced by each other: The number of visitors and the slopes available to them. The reasoning behind this model is, that skiers are attracted by three factors. These are (1) the size of the ski resorts, where they prefer many slopes to ski, (2) the density of skiers on the slopes, here the preference is empty slopes and (3) good weather, aka lots of snow.
Thus a larger ski resort attracts a larger crowd. As the ski resort managers’ goal is to maximize profit, they are interested to have as many visitors as possible and as little operating costs as possible (which translates to fewer slopes). Thus their tendency is to keep the slopes full – which might scare off visitors. Another assumption is that visitors are reacting faster on changes than resort managers can. The reasoning: new slopes needs advance planning, while visitors can use the internet to quickly book their ski vacation. Thus visitors react much quicker than the managers can.
Finally you can control the external factors weather and economy. Lots of snow will attract more people, while economic crisis will have them stay at home.