Methods

Just like you follow the signs in the forest, during an investigation you go through the investigation steps to determine what happened. Knowledge, logic and observation can help you in determine the sequence of events.

Take a look at the first tree failure example we discussed in the section Failure and Damage again. What did we observe?

• The damage pattern; we saw part of a tree where the bark was chipped off at the bottom.
• The surrounding; beavers were swimming around near the tree.

These two observations would strengthen the hypothesis that the tree failed because beavers ate parts of the tree. Now, we would like to have a way to systematically write down what we know, order, analyse and report. In the next components you will find a few options that can help you do this.

Time line

A timeline is just like your timeline on Facebook. Facebook shows your life story, as you choose to tell it or as Facebook has recorded it, in a visual, scrolling, reverse-chronologically ordered timeline. The order is important to identify as it can help in verification and validation of the event sequence. In module 2 during the investigation steps explanation, Holmes sketched a time line to determine the sequence of events. This method of chronologically writing down what and when something happened, can help in understanding the event. You may have seen another similar method being applied on television in crime series to catch a murderer.

Fault tree

Just like the timeline method, another possibility of looking at an event is by examining the event failure sequence possibilities. If you observed the board behind Holmes in module 2 you could have seen a fault tree for the truck failure. Now, let’s take a look at the tree failure discussed before. Several options can be identified which could lead to a tree failure.

1. Beaver
2. Wind
3. Old age

Methods background information

Note that it is not the goal to make a timeline or fault tree for each investigation. Depending on the failure type, these or other methods can help you in an investigation. If you want to get an overview of possible investigation methods have a look at this external link. It shows that 847 different methods have been identified.