At some level, all development process methodologies are variations on the theme of managing development within the boundaries of some common realities:
- There are only so many useful working hours per person per day that can be devoted to a project
- There is a limit to the available resources, whether in terms of people, equipment, or money, available to a project
- There is a minimum acceptable quality standard for the project when it's complete
This is sometimes expressed as the Iron Triangle of project management:
The primary concern with respect to the Speed point is time—the most common focus is probably on a project needing to be complete by a specific deadline, or there is some other time constraint that may only be surmountable by adding developers to the team (an increase in Cost), or by cutting corners (a decrease in Quality).
...