According to the BABOK® v3 guide, the purpose of specifying and modeling requirements is as follows:

This task is all about the activities you perform to analyze and create representations (textual or visual) of this information in a format that is digestible by other stakeholders groups who need the information.

Before we delve deeper into the elements of this task, let's understand how you should use the terms "requirements" and "designs" in the business analysis world.

The term "requirements" is used when the focus of the "specify and model" activity is on understanding the business needs. The outputs that are generated as a result of these types of analysis activities are referred to as requirements.

The term "designs" is used when the focus of the "specify and model" activity is on understanding the solution. The outputs that are generated as a result of these types of analysis activities are referred to as designs.

Let's consider a practical real-world example of how these terms can be used appropriately.

An organization needs to increase its number of customers. The requirement here is to increase the new customer leads generated. Because there is a focus here on the business needs, the output of the activities to understand this business need would be referred to as the requirements.

However, part of the solution to this requirement is to build a new website and to add additional search engine campaigns. These solutions would be analyzed and modeled in the form of mock screen layouts, specific marketing campaign pages, and so on. These would be example outputs where the focus of the analysis activities are on the solution and would, therefore, be referred to as designs.

Let's now consider the core elements that a business analyst should include when performing this task.