Final answer:
Traditional Systems Development Lifecycle (SDLC) is a sequential process while alternative methods like the spiral design process allow for changes and evaluation of an improved design. The spiral design process is more flexible but requires more time and resources.
Step-by-step explanation:
Traditional Systems Development Lifecycle (SDLC) is a sequential design process where each step follows the previous one in a direct sequence. It does not account for the iterative nature of many design projects. Alternative methods, such as the spiral design process, allow for changes to be made in the design and evaluation of an improved design. The advantage of the spiral design process is that the end design is often much better than the initial design, but it requires time and resources for each loop in the spiral.