One further change in the 1990 Act related to the way the ITV networking system was run. Since the 1960s, the Independent Television Companies' Association's Programme Controllers' Committee, representing the 'Big Five' network companies (Thames, LWT, Central, Granada and Yorkshire) had decided which programmes had aired in network programme time slots. This had the effect of excluding smaller ITV companies, as well as independent production companies. Following lobbying by independent producers and TVS, the Act required that ITV's scheduling be performed by a nominated person independent of the regional companies, and that a 25% threshold of independent production be required. This led to the creation in 1992 of the ITV Network Centre, a central body in charge of the network schedule, with, for the first time, a single ITV Director of Programming.