The Lr Model: proving reasonable care before an incident
When something goes wrong, the question is rarely whether a control existed. It is whether anyone can prove it existed, was reasonable, and was carried out. My research paper puts a number on that gap.
Bridging the Documentation Void: A Quantitative Approach to Residual Liability (Lr) and Fiduciary Defensibility
Richard G. Prouse
Read the paper (free) DOI 10.2139/ssrn.6175099
The idea in plain words
Organisations are judged after an incident on what their records show. A control that worked but was never written down, or was written down in generic terms, gives an investigator, insurer or court very little to go on. The paper calls the liability that remains in that situation residual liability (Lr).
The Lr Model adds a Documentation Coefficient to an ordinary risk assessment, so the strength of the evidence behind each control is scored alongside the control itself. That makes the documentation gap visible, and measurable, while there is still time to close it.
Where it is used
It is the method behind the documentation audits of Confidential Risk Consulting, used within an ISO 31000 risk-management process. The same thinking, that every claim should be traceable to its evidence, runs through TenderAxiom's Bid Check.
Questions
What is the Lr Model?
A model by Richard G. Prouse for measuring residual liability: the liability an organisation still carries when a safety or security control exists but its documentation can't prove it was carried out.
Where is the paper published?
As a working paper on SSRN, January 2026, DOI 10.2139/ssrn.6175099. It is free to read.
Is the Lr Model used in practice?
It is the method behind Confidential Risk Consulting's documentation audits, alongside ISO 31000.
My work: TenderAxiom · DutyNode · Aidfolio · Confidential Risk Consulting