Iterative Design Process

Engineering Design is the process of creating well documented and well justified solutions, based off engineering analysis, which also take into account ethical, economic, social, and environmental considerations.

- Dr. Borland

The iterative design process is a method to develop solutions for a given problem. The iterative design process focuses on developing solutions in an iterative approach, where each iteration helps to reveal more information around the situation of concern and how the designed solution will function in its intended environment. Each phase of the iterative design process informs future phases.

Needs Assessment

During needs assessment the situation of concern and problem space is explored. This part of the design process is used to develop requirements and constraints.

Synthesis

The synthesis phase is used to develop various solutions that meet the design specifications, requirements and constraints that were created during the needs assessment phase.

Design / Analysis

Design / Analysis involves reviewing and combining the solutions that were developed in the synthesis phase into viable solutions that meet the design problem definition. During this phase preliminary calculations and predictions on the performance of the system are created.

Prototyping

During the prototyping phase various prototypes are created based on how many iterations of the iterative design process have been completed. In the early cycles of the process, low fidelity prototypes are created. The further into the design process, the higher the fidelity of the prototype.

Low fidelity prototypes can be made of incredibly basic materials, software, or tools and most functionality will not be present (or will be faked). The higher the fidelity of the prototype, the closer to the final designed solution it will be.

Testing & Validation

Using the prototypes that were developed the testing and validation is used to measure the performance of the solution. It can include user testing, benchmarking, functionality testing, failure mode analysis, or anything that is deemed appropriate. The prototype should be evaluated against the requirements and constraints developed during needs assessment.

Evaluation and Recommendations

This phase documents the learning from each iteration of the design process. It is designed to inform future designs and help avoid repeat mistakes from the past. Early cycles may not be formally written, but should still be evaluated.

Note that throughout the iterative design process, you may identify a requirement that was missed. This is okay. At any point in the iterative design process, it may be beneficial to go back to the needs assessment phase. This may feel like backtracking, but it is actually working as intended. You will have learned something about the problem space that you did not before, and identifying it with each iteration will hopefully catch the largest problems the earliest, when the cost of going through all of the phases of the design process are lowest.