The last model I would like to talk about is the Waterfall Model used in designing medical devices. While this model is more tailored to medical instruments, I found this model to be quite interesting.I like that the model clearly shows that at EVERY step along the design process, the engineering designer needs to take a step back and analyze the situation with a rational mind and decide if there are any improvements to be made.The main problem with this model is that it places a huge leap in engineering design between two steps. The model goes from user needs to design input. This is a very large step to make since from user needs, objectives must be drawn. From these objectives, metrics, constraints, criteria and requirements will be created. From this, the designer would try to come up with a product design that matches these parameters. This whole process may undergo reframing and rescoping as you learn more about the problem after each iteration on the product.