Since January 2011, all DFID Department decisions to spend aid money are based on a detailed business case. DFID's Business Case is based on HM Treasury's 'five case' model. Each business case sets out and appraises the different options and mechanisms to deliver the development outcome being sought. The five interdependent cases assess the strategic, value for money, financial, commercial and management elements of each aid programme. All DFID business cases are published on our external website.