System Degradation Analysis Using the Degradation-Entropy Generation Theorem

Computing & Wireless : Application Software

Available for licensing


  • Jude Osara, Ph.D. , Mechanical Engineering
  • Michael Bryant, Ph.D. , Mechanical Engineering

Background/unmet need

The DEG methodology for system degradation analysis applies the DEG theorem proposed by Bryant et al. (2008) in a Royal Society journal, which relates the appropriate measure of degradation (e.g., battery capacity fade, grease consistency loss and fatigue failure) as a linear combination of the irreversible entropies produced by the underlying dissipative processes that drive the degradation.

Invention Description

This theorem proposes a consistent thermodynamic approach using free energies and is based on conducted experiments validating the theory. Data has been collected to estimate entropies produced by the dissipative processes for:

- Batteries (Li-ion & lead-acid): joule dissipation, thermal and electrochemical entropies

- Grease: shear work, thermal and oxidation entropies

- Fatigue of all solid components: plastic strain and thermal entropies

and the measure of degradation for each system was found to be a perfectly linear combination of the aforementioned entropies.


  • Creates a structured and universally consistent approach to all degradation and failure modeling, converting degradation and failure analyses into a geometry problem in a multi-dimensional entropy-failure space
  • Physics-based consistent characterization of all systems
  • Uses easy-to-obtain in-operation non-intrusive measurement of system’s boundary work and temperature
  • 100% accuracy in monitoring, analyzing and predicting system failure


  • Applies to ALL forms of degradation: All real processes are governed by the second law of thermodynamics, the deductive basis of the DEG theorem; hence, all degradations resulting from all real processes are governed by the DEG theorem.
  • Unifies ALL existing degradation measures: In various disciplines, process- and system-specific reliability/performance/degradation measures exist to monitor and predict failures. The DEG theorem uses the degradation coefficients Bi to link the existing measures to the ’natural’ entropy generation components in the process/system.
  • Provides a structured approach to ALL degradation/failure analysis: Same procedure, independent of process or system.
  • Establishes a critical failure entropy that consistently detects instability in all systems.

Market potential/applications

All manufacturing companies; any engineering company that wants to significantly increase profits by using Analysis-Led Design, which has recently become popular among the top companies; all battery manufacture/application

Development Stage

Lab/bench prototype

IP Status

  • 1 U.S. patent application filed