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.Stephen F. Bush, John Hershey and Kirby Vosburgh, Brittle System Analysis, 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 StressInterbyte jitter, EMI, number of slaves, etc.Amount parameter exceeds toleranceForce per unit area within a body ToughnessAbility to withstand the aboveSystem robustnessAbility to absorb energy up to failure Hardness*Constant latency, throughput with stress in toleranceLevel of performance within toleranceResistance to deformation Ductility*Gradual reduction in latency, throughput as stress exceeds toleranceLevel of performance out of toleranceFracture strain or reduction of area at fracture Plastic strainLatency, throughput are permanently degradedSystem cannot recover from degradationDeformation between particles in a body relative to length Reversible strainLatency, throughput are temporarily degradedSystem can recover from degradationSame as above, but returns to normal after force removed Brittle fractureSudden steep decline in latency, throughput Sudden steep decline in performanceThere is no reduction of area when material breaks Ductile fractureGraceful degradation in latency, throughput Graceful degradation in performanceThe area at the point of fracture gradually reduces to zero Brittleness*Hardness over ductilityRatio of hardness over ductilityRatio of hardness over ductility DeformationDegradation in latency, throughputDegradation in performanceChange in shape of a material Young's modulusStress (jitter/EMI) over reduction in latency and throughputAmount of tolerance exceeded over degradationMeasure of the stiffness of an elastic material
See also
References
Further reading Active Networks and Active Network Management Section 9.4.2.