MULTIPLE BRINE PRODUCTION AND STORAGE FACILITY LOCATION PROBLEM FOR SNOW REMOVAL
In a departure from past practice, snow plow operations are now executed in a two phase approach: a preparation phase where brine is sprayed on roads, and a snow removal phase. In order to augment existing snow removal operations by the first phase, investments in new facilities such as silos for brine storage, and equipment such as brine spreaders are required. To maximize the impact of these investments, decisions such as the optimal location of silos and the selection of appropriate equipment must be carefully considered. This thesis addresses the facility location problem only.
The benefit of investing in facilities and assigning them to locations in a network is assessed based on two premises: operations shall be expedited and brine shortage shall be avoided. Operations are expedited by providing more replenishment points for trucks so that the time for replenishment dwindles. The model is formulated as a deterministic facility location model.
The second premise takes into account that silos are cheaper than brine machines but that they are also less effective in averting brine shortage.Since they are cheaper, more replenishment points can be set up and solving the model only based on the first premise would always suggest to invest in silos. But when subsequently hitting snow storms require plenty of operations with only a few days in between, silos eventually deplete and brine shortage is imminent. The deterministic model is therefore extended to a scenariobased model incorporating variability due to weather. All possible facility combinations, so-called facility type mixes, undergo a stress test and it is assumed that when no brine shortage occurred during this stress test, the facility type mix is also appropriate for less intense weather scenarios which were not considered.
In this work, a new concept is assessed which comprises a brine machine on a boat. Such a boat helps to avert brine shortage and additionally provides a mobile replenishment point for trucks.
The model is applied to a case study for the Rhode Island Department of Transportation.