Employment by occupation can be classified according to different skills 'which are influenced by education, training, the general competencies and levels of skills required within a particular occupation. The skill level is important as one can only do specialised jobs when certain skills are attained. Skills shortages and mismatches are some of the challenges facing developing economies and posing a serious threat to economic growth and achievement of socio-economic goals.' (Gauteng Provincial Government Department of finance (2010) 'Gauteng Socio-Economic Review and Outlook (SERO)', 39)