Ministries in Swaziland, such as the Ministry of Defence and the Ministry of Health, are headed by appointees of the king. The king appoints ministers from both chambers of parliament on the recommendation of the prime minister. Based on a bicameral system – with a 55-member House of Assembly and 31-member Senate – parliament is the supreme forum of government activities. The Cabinet is collectively responsible to parliament. On the advice of the Civil Service Commission, the king appoints principal secretaries on a renewable five-year contract.