Host families: parenthood under contract

When parents fail, society has a responsibility to look after children so that they grow up in good material, emotional and social conditions. While family care is preferred, children are sometimes taken away from their families and placed in institutions or foster families for an indefinite period of time. This is the start of a special kind of family life, with temporary siblings and intermediary ties between foster parents and foster children. Who is entitled to decide on parenting skills?