Risk matrix methodology has ‘fundamental flaw’

Dr Melvyn Langford C.Eng, MIMechE, MCIBSE, who for 10 years ran his own consultancy, Healthcare Operational Risk, but previously worked for nearly four decades in the NHS (including as an estates and facilities manager) discusses the key factors that have long convinced him – and, he claims, many others – of ‘a fundamental flaw’ in the ‘5x5 risk matrix’ used for some years to establish the relative urgency of backlog maintenance in NHS healthcare facilities. In this fifth article to date on the subject for HEJ, (following publication of previous articles in the November 2009, September 2010, September 2011, and June 2013 issues), he explains, using mathematical computations, why he believes the existing 5x5 model is so ‘flawed and unreliable’.

This document advisers the reader of the mathematical fundamental flaws within the following two particular NHS guidance documents – NHS Estates. A risk based methodology for establishing and managing backlog1, and HTM 00, Policies and principles of healthcare engineering.2 Throughout the past 27 years, numerous scientists have undertaken research and developed case histories into the problems created from the matrix design recommended by these two guidance documents. These issues have been proven beyond any reasoned argument to generate information that will at best be misleading, if not completely meaningless, resulting in erroneous risk ratings. This evidence has been accepted and supported by the academic, industrial, and international standards community, which all warn against the use of this particular risk matrix.

Against this backdrop, it is indefensible, in my view, to ignore the failings within the current national policy when known, particularly when the ramifications and scale of these problems are so large. I have thus put together and circulated this article to explain and demonstrate the scale of this issue.