In the field of engineering, anticipating failure in projects is recognised as a showcase of an advanced process of making a product. Potential failures are to be identified before the development process initiates to successfully mitigate the risk. In the future, the production costs will be greatly reduced as a result of this. Because the product is solid-state, there is little to no risk of failure if proper failure prevention techniques are used.

Fault Tree Analysis is one such methodology that we will discuss today (FTA). The visual FTA approach has proven to be invaluable as a stand-alone risk technique as product and process technology becomes more complex.

History of Fault Tree Analysis

Fault Tree Analysis (FTA) is a method for analysing reliability and safety. Bell Technologies were the first to adopt this methodology. H.Watson of Bell Labs and A.Mearbs of the US Air Force were designing safeguards for the Minuteman intercontinental ballistic missile (ICBM) system in 1962. Total safety was a major concern for such a complex and dangerous technology. They developed the fault analysis method to improve their reliability analysis.

A year later (1963), Dave Haasl of Boeing Company recognized the potential of Fault Tree Analysis as a significant system for safety evaluation

What is Fault Tree Analysis?

Fault tree analysis (FTA) is a top-down detective failure analysis technique that examines an undesired state of a system by combining a series of lower-level elements using Boolean logic. The technique uses a graphic model of the pathways within a system that leads to a foreseeable, undesirable loss event. It's a technique used in the root cause analysis process.

Fault Tree Diagram

A Fault Tree Diagram (FTD) are logic block diagrams that display the state of a system in the state of its components. It uses a graphic model of pathways within a system that leads to foreseeable and undesired loss events.

The pathways connect contributory events and conditions using standard logic symbols. The basic constructs in a Fault Tree Diagram (FTD) are gates and events where the events have an identical meaning as a block and the gates are the conditions.

Fault Tree Diagram Symbols

As discussed earlier, there are two types of FTD notations events & logic gates.

A circle represents the primary failure event. A symbol that looks like a house is used to represent an external event. It's a common occurrence that you can count on. Undeveloped events denote something that doesn't need to be investigated further. A conditioning event is a restriction on a logic gate in the diagram. The Boolean relationship between the outcomes is represented by these gate symbols.

Gate symbols:

• OR gate An event occurs as long as at least one of the input events takes place
• AND gate An event occurs only if all input conditions are met
• Exclusive OR gate An event occurs only if one of the input conditions is met, not if all conditions are met
• Priority AND gate This is probably the most restrictive scenario when an event occurs only after a specific sequence of conditions
• Inhibit gate An event will only occur if all input events take place as well as whatever is described in a conditional event

Steps to follow when conducting Fault Tree Analysis

Read Steps and Benefits of Fault Tree Analysis:  https://www.6sigma.us/fault-tree-analysis/all-about-fault-tree-analysis/