I recently attended a training course and the trainer introduced a monitoring tool which he had been taught about a number of years ago and referred to it as a ski slope chart. The chart had accident reduction on the Y-axis and time on the x-axis and the reduction of accidents plotted against three inputs. Namely Legal compliance at the top followed by managerial system controls below this and finally worker input giving the final slope. I have tried to find reference to this and to where it originates. To-date I have not had any luck. I was wondering if anyone over the years has come across a publication referring to this type of chart. thanks John