Design rigour

Safety integrity levels (SILs) and design assurance levels (DATs) are allocated to systems commensurate with the significance of any residual malfunctions. Essentially we establish the safety significance of the design and initiate a commensurate amount of design rigour to minimise the risk of malfunction and to concentrate effort where it is most needed. 

Design rigour Extent (quantity and quality) of effort during the design process. 

In this section we give a brief survey of the mathematical apparatus of Graph Theory. Since this article is "application-oriented , and thus is designed for the chemical community at large, mathematical rigour is omitted whenever possible. 

Tensile strength is not the most important element of a textile fiber. Important it is, but there are other factors of equal importance, such as flexibility, handle, dye-uptake, and moisture absorption/desorption. In fact, in many cases, even though the material specification is designed with a high emphasis on tensile properties, quite often the rigours of use come nowhere near the product s tensile capabilities. 

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