The disease PRRS has long been a problem faced by pork producers. The disease reduces productivity of the swine herd, and costs are spent on preventing and treating the disease, both of these factors cut into producer profits. The elimination of PRRS from a swine herd is only a temporary solution as the disease is almost always is able to penetrates swine dense areas, even with tightening and improving bio-security measures. Despite the impact of the disease, little is known about how it is spread and how it can be prevented. Aerosol transmission is said to be the way the disease travels, but this has never been backed with any empirical evidence. This paper attempts to show how breaking down the spread of the PRRS virus into smaller parts can make it easier to understand. It is suggested that to understand PRRS movement, we must first learn: Number of organisms aerosolzed by an infected pig over units of time, the rate of inactivation of airborne organisms under specific environmental conditions: temperature, light, relative humidity, dust, etc, the rate of dispersion of infectious particulates and direction of air flow, and the number of viable organisms required to infect the next susceptible pig. These factors are quantitative values making estimations possible although some of the data required must still be obtained. This information can be crucial, if a disease begins to spread predictions can be made about its range and preventive actions  can be taken.