Or tried and trusted? There is a big difference.
‘Tried and trusted’ is reassuring – ‘We’ve used it before and we know how it works’. BUT also carries the risk of complacency, of failing to adapt to situations, of staying stuck in a comfortable routine (rut).
‘Tried and tested’ requires challenge. It risks exposing our assumptions and upending them. It means we might need to put more effort in and re-designing can be expensive. BUT testing builds resilience and confidence.
Testing needs to be repeated to avoid the elephant trap that is ‘tried, tested (once) and trusted (forever)‘.