Bow-tie diagram

[1][7] Other sources point to Derek Viner (in the same year) at the then Ballarat College of Advanced Education (now the Federation University of Australia), who drew it as an aid to visualization of his generalized time sequence model (GTSM) for damage processes.

The bow-tie diagram introduces the concept of a central energy-based event (the "bow tie knot") in which the damaging properties of the energy are no longer under control so that they result in outcomes and consequences.

[5][3] Royal Dutch Shell is considered to be the first major company to successfully integrate bow-tie diagrams into their business practices, at least since the early 1990s.

[1][9][10] Bow-tie diagrams contribute to the identification, description and understanding of the different types of hazards that can arise in a given situation, facility or production process.

[12] Derek Viner resolved this circularity by defining the event as "the point in time when control is lost of the potentially damaging properties of the energy source of interest."

The need for energy sources in any damage process had been noted by Lewis DeBlois as early as 1926[13] as well as Gibson[14] and Haddon[11] in the decade prior to the introduction of the bow-tie diagram.

Possible mechanisms for breach of containment, shown to the left, include structural degradation (abrasion, corrosion, fatigue), spurious pressurization above design limits, inadvertent opening, etc.

Outcome (right-hand side) control measures in this example would include nearby structures designed to withstand modelled blast overpressure.

Bow-tie diagrams are typically a qualitative tool, used for simple damage process analysis as well as for illustrative purposes, such as in training courses to plant operators and in support of safety cases.