A Problem domain is a general term that refers to all the issues related to the problem that the project is supposed to help solve. It is the responsibility of the project participants to establish the

1. problem statement context and
2. scope

that determine how much of the problem domain will be included in the project.
Occasionally, the phrase problem domain will be used in a more inclusive manner to mean "this type of problem." For example, the problem statement might refer to a specific flower shop. But while discussing that flower shop, I might refer to common flower shop practices, that is, practices that are typical for similar businesses and constitute a problem domain that is unique to these businesses.

In this technique, various objects that occur in the problem domain and the solution domain are first identified and the different relationships that exist among these objects are identified. The object structure is further refined to obtain the detailed design. T he OOD approach is credited to have several benefits such as lower development time and effort, and better maintainability of the software.