| Regression testing - | (Software Engineering) tests that are conducted repeated to ensure that a change has not introduced side effects |
| Reliability - | (Software Engineering) a measure of the degree to which software operates reliably over some period of time |
| Requirements analysis - | (Software Engineering) a modeling activity whose objective is to understand what the customer really wants |
| Requirements engineering - | (Software Engineering) the activities required to elicit, elaborate, negotiate, specify, and validate system or software requirements |
| Resources - | (Software Engineering) anything that is required to get the project done, people, hardware, materials, information, etc. |
| Reusability - | (Software Engineering) the ability to reuse an already-existing program component in another application |
| Reusable components - | (Software Engineering) configuration items that are reusable |
| Reverse engineering - | (Software Engineering) trying to develop design models or an understanding of design using program code as a starting point |
| Risk - | (Software Engineering) a potential problem or occurrence that put a project in jeopardy |
| Risk analysis - | (Software Engineering) a techniques for identifying and evaluating risks |