What is the theory of "multiple causation"?

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The theory of "multiple causation" refers to a single accident that may involve various contributory factors, causes and sub-causes, where this certain culmination of factors manifest into aircraft accidents/incidents. It could also refer to contributory factors combining together in a random manner, causing accidents. According to this theory, the contributory factors can be grouped into the following two categories, the first category includes factors pertaining to the worker or behavioral factors, such as improper attitude, lack of knowledge, lack of skills, and inadequate physical and mental condition. While the second category, known as environmental factors, includes improper guarding of other hazardous work elements and degradation of equipment through use and unsafe procedures. The major contribution of this theory is to bring out the fact that rarely, if ever, is an accident the result of a single cause or act. Accidents are often an interrelated series of events that results in an accident. By using the multi cause concept, it allows investigators to determine at which point was there a lapse in safety. This can be illustrated using Dr. Reason's Swiss Cheese model, where the latent condition will be escalated by errors and wrong decision that will lead to a catastrophic consequence if they are not contained by the layer of defenses set in place. There is no single exposure data/factor that paints the entire safety picture of air travel. Most of the aviation safety programs are a multi cause and takes a look at the big picture as it allows for a systematic approach to managing safety and making the necessary changes to ensure higher safety standards.