What does the pv value signify?

The pv value is the product of velocity (V) and pressure (P). This value indicates the heat generated in the bearing per unit of time. For plain bearings, a maximum pv value is usually indicated. This is the amount of heat that can be removed per time unit due to the heat dissipation capacity of the materials involved. If the heat generated due to movement under load is now greater than the heat that can be dissipated in the same time, the bearing point heats up until the components fail. The pv value makes it possible to say whether a plain bearing is suitable for movement in the bearing point but, unfortunately, it says nothing about the durability of the plain bearing in the application: Does a plain bearing that has a maximum pv value that is two times higher last longer than one whose pv value is only 1.5 times higher? How many safety factors should be planned for?