Ergonomics is sometimes described as "fitting the system to the human," meaning that through informed decisions; equipment, tools, environments and tasks can be selected and designed to fit unique human abilities and limitations. Typical examples in the "physical ergonomics" arena include designing a lifting job to occur at or near waist height, selecting a tool shape that reduces awkward postures, and reducing unnecessary tasks and movements to increase production or reduce errors and waste. "Cognitive ergonomics," on the other hand, focuses on the fit between human cognitive abilities and limitations and the machine, task, environment, etc. Example cognitive ergonomics applications include designing a software interface to be "easy to use," designing a sign so that the majority of people will understand and act in the intended manner, designing an airplane cockpit or nuclear power plant control system so that the operators will not make catastrophic errors.