(Ashgate, 2009, ISBN 978-0-7546-7678-2)
As you can tell from the title, this book picks up the ETTO idea that already was mentioned in the 2004 book and Hollnagel elaborates on the idea. Sources of success and failure are often the same. Coping with competing objectives. From rationality to ETTOing. Are humans irrational? Examples to ETTOing in the practice. The usefulness of performance variability. ETTO in the past and future. Along the way Hollnagel also introduces another acronym: WYLFIWYF and of course he paves the way for Safety-II. Essential reading.
(Will do a longer summary/review when time allows...)