Throughout the first 70 years of developments in machine milking systems (1889–1959) very little attempt was made towards either the mechanization or automation of cleaning. Aspects of mechanical efficiency were given much greater attention and, as long as the labour demands of cleaning the machine and the milking premises were acceptable in terms of cost and effort, no action was considered necessary. It is, therefore, not surprising that although four distinct phases of development in machine milking systems emerged over these years, cleaning of both the premises and equipment remained essentially a manual operation (Table 1).