The "forty principles" of TRIZ are basic engineering parameters of common objects, such as weight, length, and manufacturing tolerances. TRIZ methodology claims that by studying an individual parameter which is causing a problem (e.g., the weight of an object needs to be reduced), and the other parameters which are in conflict with it (e.g., lower weight would require thinner material, which is more likely to undergo catastrophic failure if overstressed), engineering solutions can be created for invention problems.