Because walmart is a global company,this company need to grow in different countries and it is necessary to accept a union.Walmart signed a memorandum with the ACFTU allowing unions in walmart,and also negotiates with unions in Brazil,Chile,Mexico,Argentina,the United Kingdom,abd South Africa.Then walmart increase their right to stop business relationships with some suppliers immediately if they discovering a violation.On the other hand,walmart also requires all suppliers to have an independent agency assess the building and electrical safety conditions of their factories.