TABLE OF CONTENTS Cause and effect tree analysis (described in detail in Appendix B) is a good analysis technique for equipment-, machinery-, and software-oriented problems. Its structure works very well when dealing with the logical behavior of equipment and software. However, cause and effect trees have one major drawback: they do not show the relative timing of events.
Timing is usually important when people are involved in incidents. It is also important in most safety and environmental incidents. Timelines (described in detail in Appendix C) are a simple tool for explicitly addressing the timing of events. Causal factor charting also addresses the timing of events. In addition, causal factor charting incorporates the logic of cause and effect trees. In other words, this methodology combines timing and logic into one technique.
Causal factor charting establishes the relative timing of events and sets the time frame of interest for the incident. It sorts the data we have collected (events and conditions) into the following categories:
Loss event(s)
Main events and conditions
Reasons why the main events occurred and the conditions existed
Other significant events
Unimportant, insignificant events that do not affect our analysis and are not added to the chart
Like cause and effect tree analysis, this method helps investigators gather and analyze the data required to identify causal factors (CFs) and items of note (IONs).
Causal factor charts are constructed by working backwards, starting with the loss event/condition and working backwards in time. This is essentially the...
