Non Deterministic Approaches

In all phases of engineering analysis of a technical component over its product lifetime, all decisions are crisp. They are either yes/no decisions or they involve the specification of precise values or a range of values. Availability of data is usually insufficient to support a statistical interpretation of design decisions. Generally speaking, the interval or the fuzzy concepts is most appropriate for technical analysis.

Statistical interpretation may be relevant in three out of the six stages that are identified in section "Overview of stages in the engineering process":

• the specification of design loads or the specification of a probability of failure may be based on a statistical interpretation
• product quality and control may lead to the establishment of quality distribution over the full range of nominally identical products
• the decision to replace a component during its service life may be based on statistical information gathered previously with similar products