What failed
Therac-25
1985 – 1987A deleted safeguard didn't remove the hazard — it relocated it onto an operator who couldn't see it coming.
Case Studies
Capability is a system parameter.
Learning engineering is a toolbox, not a single tool — a dialogue between the disciplines that build complex systems and the sciences of how people come to know and do. LENS extends that work to next-generation systems. These cases are how we show what it looks like: each one a system that succeeded or failed on what people could do inside it.
Grounding. Every study is drawn from Capability Matters: A Casebook — the salient details, the Learning-Engineering-Lens reading, and any disclosures carried through faithfully from the peer-reviewed and investigative record. One failure and one success per domain; fourteen in all.
1 Healthcare & Patient Safety
What worked
Keystone ICU / Pronovost Checklist
2004 – presentA five-item checklist and a nurse's authority to stop the procedure cut deadly ICU infections to near zero.
2 Education, Training & the Learning Workforce
What failed
inBloom
2014The technology worked flawlessly. It still collapsed in fourteen months — because no one engineered the trust.
What worked
Cognitive Tutor / Carnegie Learning
1990s – presentCognitive science turned into software that watches a student think — and a generation of evidence that it works.
3 Aviation & Aerospace
What failed
Boeing 737 MAX / MCAS
2018 – 2019346 people died because pilot training was engineered out of a jet to protect a commercial promise.
What worked
Crew Resource Management & CAST
1981 – presentAviation engineered how a crew talks, decides, and challenges authority — then built the measurement loop that kept finding what to fix next.
4 Defense & National Security
What failed
USS Vincennes & Iran Air Flight 655
1988The most advanced combat system afloat showed the truth. Under stress, its operators read the opposite.
What worked
DARPA Digital Tutor
2009 – 2014A one-on-one digital tutor compressed years of IT expertise into sixteen weeks — and its graduates beat veterans.
5 Industry, Energy & Enterprise Systems
What failed
Knight Capital Trading Loss
2012$440 million gone in 45 minutes — from a deployment nobody had the capability to catch in time.
What worked
Toyota Production System / Andon Cord
1950s – presentPulling the cord doesn't stop the line. What it buys is a guaranteed answer within the work cycle — and that is the design.
6 Disaster Prevention & Recovery
What failed
Deepwater Horizon
2010Eleven dead, and every safeguard had quietly drifted until none of them caught the others.
What worked
Navy SUBSAFE
1963 – presentAfter losing 16 submarines, the Navy made safety requirements non-negotiable — and lost one in the sixty years since.
7 Algorithms, Governance & Public Systems
What failed
UK Post Office Horizon Scandal
1999 – 2015For two decades, 'the computer said so' was enough to imprison innocent people. No one could challenge it.
What worked
Estonia X-Road
2001 – presentNear-total digital government — and an honest warning that today's success is tomorrow's legacy system.