The Guidance on Emergency Assessment gives guidance on when and how to conduct assessments during emergencies.
Given the need to make early programming decisions in a fluid environment and with imperfect information, emergency assessments need to be iterative. In most cases, two or three stages of assessment may be required, sometimes many more if the situation keeps changing and requires reassessment of needs. This guidance focuses on the early assessments at the initial stages of the response, which typically consist of two or three stages over time. Their timing principally depends on access factors but usually the preliminary stage is initiated in the first day or two after the emergency; the second stage (first field assessment) takes place during the first few days to a week; and more in-depth sectoral assessments take place over the next few weeks to a month. The different stages of assessment vary not only in time but also in their purpose, methods, approach, etc.
All assessments should be focused and time-bound: the process is iterative, not continuous. However, once a program starts, a process of light contextual assessment should be built into ongoing monitoring of the response, and may trigger renewed assessments if the situation changes.