Even when all the resources required to solve or alleviate a problem are available, it is frequently very difficult, if not impossible, to deliver the commodities or services to the people in need. This is true of food (during food shortages or famine), medical care, services (whether water, electricity, sanitation, or road), information or education.
In attempts at famine relief in Ethiopia, for example, many villages were not accessible by road and airlifts were inadequate. In addition, relief work had to cope with illegal diversion of supplies.