Things that have never happened before happen all the time.

Scott D Sagan The Limits of Safety

Spad situation

Drive a mile in my seat: signal design from a systems perspective.

A paper by Dr Anjum Naweed and John Aitken.

sign1512 1

You can get lonely out there!

Keeping in communication with people who are in isolated locations.  A paper by John Aitken.

Red and green buttons


A paper by presented to the International Railway Safety Council.



Enhancing error tolerance, error detection and error recovery to together produce system safety.

Engineering systems have long relied on redundancy and diversity to achieve high levels of reliability.  The effects of each of these techniques can be modelled mathematically and their cost-effectiveness can be evaluated. 

Resilience extends these concepts, taking into account the system in its environment, its interaction with its users and with other systems.  It involves enhancing error tolerance, error detection and error recovery together to produce system safety. 

These concepts are discussed in some extracts from books and journals in Resilience Engineering.

Things that go Right

When we think about safety, we often focus on failures.  Perhaps that is because we see safety as a a description for the abscence of harm, rather than the embodiment of success.  Thorough engineering design, taking time to fully understand the environment and the system are mechanisms to ensure success.  They are often called "good engineering practice" but there is more to it than that.  Experience and insight play a significant part; so does willingness to look across disciplines; enthusiasm to understand the underlying principles and commitment to learning more about each aspect of a system.  We work with experienced colleagues from many disciplines to ensure that our understanding is broad and based on substance.

"The enemy of safety is complexity."

 Behind Human Error, Woods et al, Ashgate 2010 p 23

"Knowledge and error flow from the same mental sources, only success can tell one from another."


Ernst Mach, 1905