The framework proposed by the International Water Association (IWA) task force for the analysis and selection of appropriate sanitation systems is called Sanitation 21. It is a comprehensive approach for the assessment of planned or existing sanitation situations. However, it does not provide in-depth guidance for planners and operators. The Sanitation 21 task force argues that technical planners and designers have to develop more sophisticated planning systems that respond to the needs of rapidly growing cities. As regards the human and political context, this will require a change in the manner of making technical decisions. Quality and effectiveness of sanitation investments are not particularly about technologies (although the appropriate application of technology is important), but are rather about developing an explicit understanding of what the objectives of a system are and then designing a system which meets those objectives.