Swachh Survekshan is an annual survey of cleanliness, hygiene and sanitation in cities and towns across India. It was launched as part of the Swachh Bharat Abhiyan, which aimed to make India clean and free of open defecation. The first survey was undertaken in 2016 and covered 73 cities; by 2020 the survey had grown to cover 4242 cities and was said to be the largest cleanliness survey in the world. In a bid to scale up the coverage of the ranking exercise and encourage towns and cities to actively implement mission initiatives in a timely and innovative manner, Ministry of Housing and Urban Affairs (MoHUA) is now in the process of conducting the sixth edition of the survey to rank all cities under Swachh Bharat Mission-Urban (SBM-U) with Quality Council of India (QCI) as its implementation partner.