Are the requirements or specifications for a solution to be successful.

Are limitations put on the design of a solution and are often factors that are beyond the control of the engineers (cost, energy, space, and availability of tools and materials).

Is a process of comparing the predicted benefits and costs of a solution. The best solution is one that has more benefits than costs.

Some criteria are identified as more important than others and should be considered with more value.

A model that is used to test a design. Engineers use models to explore processes that happen too slowly, too quickly, or on a scale too small or too large to observe directly. They also use models in situations that are potentially dangerous. Engineers sometimes use more than one type of model to explore a design.

A design sometimes does not behave in the expected way and may need to be redesigned.  It is very common for a design to go through multiple redesigns, or iterations, before a final solution is determined.

Is a description of how close a measurement is to an accepted value.

Is the confidence that can be placed in the truth of scientific findings.

Is the degree to which something produces benefit compared to its cost.

Is a situation in which you must choose between two things, giving up one in exchange for the other. The most cost effective solution finds the best compromise between costs and benefits.