The Swedish constitution requires that the Prime Minister appoints one of the Ministers in the cabinet as Deputy Prime Minister (sometimes inofficially known as Vice Prime Minister), in case the Prime Minister for some reason is prevented from performing his or her duties. However, if a Deputy Prime Minister has not been appointed, the Minister in the cabinet who has served the longest time (and if there are several with equal experience the one who is oldest) takes over as head of government (these are marked in italic in the table below).
Unlike other Vice Head of Governments, the Swedish Deputy Prime Minister does not have any assignments and usually occupies another post in the cabinet. It also occurs that the Deputy Prime Minister takes over some of the Prime Ministers duties temporarily, for instance when the Prime Minister is on holiday.