text: FSM services can be provided as demand based (often called on-request, on-call, on-demand, ad-hoc or non-scheduled) or scheduled (also known as regular) desludging, or a combination of both. Under either mechanism, OSSFs are desludged on a periodic basis or when the household requests it or due to inspection by a competent authority indicates desludging is needed.
  An analysis of 20 FSM Innovation Case Studies and research and advocacy of successful programs carried out by Oxfam Philippines has demonstrated that common elements for successful FSM programs include:
  * Well formulated and practical policy, rules and regulation: While these are essential they are almost useless, even counterproductive, on their own, and must be supported by complementary factors such as those below;
  * Local leadership and clearly mandated and resourced institutions to manage services, even where actual services are delivered by the private sector;
  * Partnerships between stakeholders contributes to developing services at scale, building community confidence and achieving sustainability;
  * A sustained program of community engagement, marketing and awareness raising is as essential to FSM as sludge treatment – but is frequently under-valued, under-budgeted and sometimes abandoned after an initial period;
  * Capacity-building for FSM service providers helps ensure that they can effectively meet all segments of demand and achieve long-term viability. This may include training in both technical matters and business management, and the facilitation of capital formation through grants, equipment leasing, loan guarantees and other financial instruments;
  * Tariffs that are pro-poor and representative of operational costs for providing the service;
  * Technology that is appropriate to the capacity to operate and maintain the system and the realities of the value chain.