ESDU 81040 is the seventh Item in an integrated group that deal with the stability and response of linear systems. Its aim is to assist those with limited experience in the field of analysis of dynamic systems, to understand and use the various techniques available for the assessment of their stability and response. It illustrates the earlier parts of the group by the use of worked examples. The data can be applied typically to control system analysis, stability of surface and aerospace vehicles, servomechanisms, and vibration analysis. The range of data applicability includes any system that can be described by linear differential equations with constant coefficients, such as many mechanical, electrical, chemical, biological, sociological or other systems.