Operating any system beyond the design limits causes irrecoverable damage to the components due to unintended exposure to overload, overheating, corrosion and wear. Consequently, failures due to overload conditions; stress rupture, and creep and thermal shock caused by overheating; corrosion damages such as pitting corrosion, hot corrosion, stress corrosion cracking; and wear, erosion and fretting damages caused by wear and tear are commonly encountered. The most important life-limiting factors emerging from operational abuses are listed in Figure 6.2.