Engineering design is the method that engineers use to identify and solve problems. It has been described and mapped out in many ways, but all descriptions include some common attributes: 
Engineering design is a process. This powerful approach to problem solving is flexible enough to work in almost any situation. Engineers learn important information about both the problem and possible solutions at each step or phase of the process.
Learn about different models of engineering design.
Engineering design is purposeful. The process always begins with an explicit goal. If it were a journey, it would be one with a specific destination – not a random sightseeing trip.
Engineering design is “design under constraint.” Designers must choose solutions that include the most desired features and fewest negative characteristics. But they must stay the limitations of the given scenario, which could include time, cost, and the physical limits of tools and materials.
Engineering design is systematic and iterative. It is a process that includes steps that can be repeated, although not always in the same order. Steps include things like planning, modeling, testing, and improving designs.
Engineering design is a social, collaborative enterprise. This process is often done in small teams that include people with different kinds of knowledge and experience. Designers are continuously communicating with clients, team members, and others.