A needs assessment is a systematic process for determining and addressing needs, or "gaps", between current conditions, and desired conditions, or "wants".

Needs assessments can help improve policy or program decisions, individuals, education, training, organizations, communities, or products.

There are three types of need in a needs assessment: perceived need, expressed need and relative need.

Considered the "father of needs assessment", Roger Kaufman developed a model for determining needs defined as a gap in results. Kaufman argued that an actual need can only be identified independent of a proposed solution. According to Kaufman, to conduct a good-quality needs assessment, determine the current results and articulate the desired results; the distance between results is the actual need. Once a need is identified, then a solution can be selected.

Extensive research uses a large number of cases to determine the characteristics of a population, while intensive research examines one or a few cases in depth.

Once the group has identified needs, they then generally turn to intensive needs assessment in order to rank the needs. This part of the research is concerned with examining the depth of the need, and potentially required resources.

A needs chain model is a framework that allows organizations to simultaneously consider the individuals' needs within an organization, and the organization's needs, in order to prioritise resources and identify areas of improvement for the organization.

A needs chain model is composed of aligned horizontal and vertical processes. The horizontal needs are: