The primary challenges in slum upgrading are achieving some kind of coherence in the community and finding solutions to a wide range of needs. Slums are not homogeneous, there are many diverse interests that exist in the slums. To the poor that are simply looking for a decent place to live, there may be criminal elements that take advantage, or landlords that make a small fortune renting shacks to people over time. All diverse interests must be properly understood and brought into the planning process. The most productive process would be negotiated development, participants will negotiate their rights and the different interests that need to be brought into the equation. It is also beneficial if upgrading activities are city wide and involve partners beyond the slums themselves, which is especially important in implementation. There must be incentives for agencies to work with the poor; good communication, coordination among stakeholders and clearly define the roles for the various agencies involved.