This article needs additional citations for verification. (May 2017)
Brittle systems theory creates an analogy between communication theory and mechanical systems. A brittle system is a system characterized by a sudden and steep decline in performance as the system state changes. This can be due to input parameters that exceed a specified input, or environmental conditions that exceed specified operating boundaries. This is the opposite of a gracefully degrading system. Brittle system analysis develops an analogy with materials science in order to analyze system brittleness. A system that is brittle (but initially robust enough to gain at least some foothold in the marketplace) will tend to operate with acceptable performance until it reaches a limit and then degrade suddenly and catastrophically. The table below illustrates the concept behind the analysis using an example of a communication system.
|Materials Science||Target System||Brittle Systems Analysis||Materials Science Quantification|
|Stress||Interbyte jitter, EMI, number of slaves, etc.||Amount parameter exceeds tolerance||Force per unit area within a body|
|Toughness||Ability to withstand the above||System robustness||Ability to absorb energy up to failure|
|Hardness*||Constant latency, throughput with stress in tolerance||Level of performance within tolerance||Resistance to deformation|
|Ductility*||Gradual reduction in latency, throughput as stress exceeds tolerance||Level of performance out of tolerance||Fracture strain or reduction of area at fracture|
|Plastic strain||Latency, throughput are permanently degraded||System cannot recover from degradation||Deformation between particles in a body relative to length|
|Reversible strain||Latency, throughput are temporarily degraded||System can recover from degradation||Same as above, but returns to normal after force removed|
|Brittle fracture||Sudden steep decline in latency, throughput||Sudden steep decline in performance||There is no reduction of area when material breaks|
|Ductile fracture||Graceful degradation in latency, throughput||Graceful degradation in performance||The area at the point of fracture gradually reduces to zero|
|Brittleness*||Hardness over ductility||Ratio of hardness over ductility||Ratio of hardness over ductility|
|Deformation||Degradation in latency, throughput||Degradation in performance||Change in shape of a material|
|Young's modulus||Stress (jitter/EMI) over reduction in latency and throughput||Amount of tolerance exceeded over degradation||Measure of the stiffness of an elastic material|
- Active Networks and Active Network Management Section 9.4.2.