Manual labourManual labour (in Commonwealth English, manual labor in American English) or manual work is physical work done by humans, in contrast to labour by machines and working animals. It is most literally work done with the hands (the word manual coming from the Latin word for hand) and, by figurative extension, it is work done with any of the muscles and bones of the human body. For most of human prehistory and history, manual labour and its close cousin, animal labour, have been the primary ways that physical work has been accomplished.
Human factors and ergonomicsHuman factors and ergonomics (commonly referred to as human factors engineering or HFE) is the application of psychological and physiological principles to the engineering and design of products, processes, and systems. Primary goals of human factors engineering are to reduce human error, increase productivity and system availability, and enhance safety, health and comfort with a specific focus on the interaction between the human and equipment.
Socialist economicsSocialist economics comprises the economic theories, practices and norms of hypothetical and existing socialist economic systems. A socialist economic system is characterized by social ownership and operation of the means of production that may take the form of autonomous cooperatives or direct public ownership wherein production is carried out directly for use rather than for profit. Socialist systems that utilize markets for allocating capital goods and factors of production among economic units are designated market socialism.
Interchangeable partsInterchangeable parts are parts (components) that are identical for practical purposes. They are made to specifications that ensure that they are so nearly identical that they will fit into any assembly of the same type. One such part can freely replace another, without any custom fitting, such as . This interchangeability allows easy assembly of new devices, and easier repair of existing devices, while minimizing both the time and skill required of the person doing the assembly or repair.
