What is Requirements Reusability and what is it used for?

Requirements reusability is defined as the capability to use in a project requirements that have already been used before in other projects. This allows optimizing resources during development and reduce errors.

Most requirements in today's projects have already been written before. In some cases, reusable requirements refer to standards, norms and laws that all the projects in a company needs to comply with, and in some other, projects belong to a family of products that share a common set of features, or variants of them.

Requirements Reusability modes

• COPY AND PASTE

There are several ways of reusing requirements, and copy and paste is the most widely used technique. Even though very basic, it may be a good starting point. There are multiple variants of this method, such as copying and pasting in read-only mode.

• COPY AND LINK

An advanced evolution of the copy and paste is to be able to keep a reference from the pasted requirement to the original one. This is a much more powerful option, as it will allow us to create a branch (a diverging version with the same unique identifier) from the original requirement, but still receive updates if the original requirement is modified. This will allow us to keep working on our own branch, or merge to the original one at any point in time.

This is a extremely efficient way of performing a change and populating it to all the ongoing projects in the company, and specially useful to deal with product variants and branches.

• LINK

This mode allows to display a representation of a set of requirements from another project in read-only mode. Any changes made to the original requirements are automatically populated to the rest of the projects reusing them. This mode is specially useful when dealing with standards and norms, in which projects need not to modify them, but need to make sure they keep up to date.

• SHARE

This mode allows projects to share the ownership of a set of requirements, being requirements editable and automatically available to all the projects at the same time.

Reuse beyond requirements

Requirements reuse is a matter of reusing much more than just plain lists of requirements. Requirements reusability consists of reusing requirements and all that comes with it, including requirements, tests, and use cases derived from the original ones, and all the traceability between them; attributes and hierarchy.