What's the difference between characteristics of a material and the working properties of a material?

The characteristics of the material comes from data collected and represented in a graphical form. From one extreme to the other, i.e. material property against time, etc. Now from these characteristics we can find the best working properties of the material at hand from the graph. This is between the extremes, i.e. - in the middle - below max and above min. like an average. This is region where you should get the best working properties of the material. A longer life or suitable area to work with for the material to maintain its original properties.