top of page
  • John Kingston

Information resides in difference

Recently, I looked at an accident in which an experienced person did something unforeseeable. The equipment, procedure and people were the same, but a change in work conditions changed team members’ roles in the team.

Change analysis is quick and can lead to valuable insights. Those light bulb moments happen often enough to make it worth talking about. Many people do it intuitively, but direction with a light touch can make it work even better.

In change analysis, one situation is compared to another. This might be to compare the situation at the time of the accident to an earlier situation or another set of circumstances. Or both. So, if ‘Team A’ has an accident, the investigator can look at how it performed work on an earlier job, or compare its approach to that taken by another team. Some differences will lead you to causally relevant facts, but watch out for coincidences and red herrings.

Like other inductive approaches, the process of change analysis is a bit elusive and can seem too loose. Novices, especially those in the middle of investigating something serious, want to find all the causes, but they also want repeatable, respectable results. Perhaps this is why written procedures for change analysis tend to be too heavy. Their writers try to put on rails something that only works well when analysts are free

to jink and jump.

It helps to have a bit of structure. However, keep it simple until the specific case calls for more. You could use the Nertney Principle headings—a basic set of four prompts: people, equipment, procedures and working conditions. More detailed, but widely applicable, is Maurice Bullock’s set of eight factors. You can find it on page 14 of his 1981 text. And, as Maurice suggests, you could choose your own.

13 views0 comments

Recent Posts

See All


Post: Blog2_Post
bottom of page