Failure design stage

Premature failure can also occur as a result of lack of attention to design. Facilities should, therefore, be provided for ventilatory drainage of water (rain, condensation, etc.), and all structures should be designed so as to permit ready access for repainting. Due consideration by architects and structural engineers at the design stage can indeed help to obviate certain of the causes of paint failure mentioned in this section (see also Sections 9.3 and 11.5). 

The commonest cause of impredicted corrosion problems is the failure to define, accurately, the chemistry of process streams, including startup, shutdown, and transient conditions, or to anticipate changes in chemistry at specific locations in equipment. The corrosivity of a process stream is often determined by its minor components, e.g., the presence of lOs-lOOsppm chlorides can promote localized corrosion of stainless steels and other passive alloys. It is important that minor components are defined, quantified, and evaluated at the design stage, including their possible local concentration such as in distillation and separation equipment. 

HAZOP can be very flexible. It is valuable in the design stage and in assessing the hazard potential of operational failures of individual items and the consequential effects on the whole. 

The conceptual design of a process is the most responsible for the success or failure of the whole project. Therefore, an unfortunate decision at this stage will be paid later at much higher cost. The economic evaluation of the conceptual design stage is often called preliminary cost estimation. This is also the object of the present chapter. 

Most of the strategies devoted to managing risk in projects at the design stage target variability. One very popular tool is known as six-sigma (Pande and Holpp, 2001). Companies also make use of failure mode effects analysis (Stamatis, 2003), which is a procedure originated at NASA in which potential failures are analyzed and measures to... 

The design for inspectability procedure noted above starts from the assumption that a list of defects to be detected can be developed at the product design stage, perhaps from a failure modes and effect analysis (FMEA) of the product s components. These defects (D, D, represents the challenges to the test and inspection system because all must be detected, and detected at the appropriate stage of manufacture. Only three components of the inspection system can be changed, or changes can affect ... 

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