Quality Function Deployment (QFD) or another type of requirements definition process is used to define the requirements or technical characteristics of a product. A more complete specification may be prepared. These requirements, specifications or technical characteristics are then used as the basis for developing various product concepts. Product benchmarking, brainstorming, and research and development are sources for new product concepts. Once concepts are developed, they are analyzed and evaluated. Cost studies and trade studies are performed. The concept selection matrix can be used to help with this evaluation process. This overall process is shown below:
The concept selection matrix shown below lists the product requirements or technical characteristics down the left side of the matrix. The technical characteristics are derived from the QFD product planning matrix. The concept alternatives are listed across the top. Each alternative is rated on how well it meets the technical characteristics or requirements.
The concept selection matrix and this process is part of DRM Associates’ QFD training and Product Development Toolkit software tools.
The specific steps for concept development and selection are as follows:
- Based on the product requirements for technical characteristics, develop concept alternatives for the new product. Consider not only the current approach and technology, but other alternative concept approaches and technology. Use brainstorming. Conduct literature, technology, and patent searches. Use product benchmarking to identify different product concepts. Develop derivative ideas. Perform sufficient definition and development of each concept to evalaute against the decision criteria determined in the next step.
- Evaluate the concept alternatives using the Concept Selection Matrix. List product requirements or technical characteristics from the Product Planning Matrix down the left side of the Concept Selection Matrix. Also add other requirements or decision criteria such as key unstated but expected customer needs or requirements, manufacturability requirements, environmental requirements, standards and regulatory requirements, maintainability / serviceability requirements, support requirements, testability requirements, test schedule and resources, technical risk, business risk, supply chain capability, development resources, development budget, and development schedule.
- Carry forward the target values for the product requirements or technical characteristics from the Product Planning Matrix. Add target values as appropriate for the other evaluation criteria added in the previous step. Also bring forward the importance ratings and difficulty ratings associated with each product requirement or technical characteristic from the Product Planning Matrix. Normalize the importance rating by dividing the largest value by a factor that will yield “5” and post this value to the “Priority” column. Review these priorities and consider any changes appropriate since these are the weighting factors for the decision criteria. Determine the priorities for the additional evaluation criteria added in the prior step. List concepts across the top of the matrix.
- Perform engineering analysis and trade studies. Rate each concept alternative against the criteria using a “1” to “5” scale with “5” being the highest rating for satisfying the criteria.
- For each rating, multiply the rating by the “Priority” value in that row. Summarize these values in each column in the bottom row. The preferred concept alternative(s) will be the one(s) with the highest total.
- For the preferred concept alternative(s), work to improve the concept by synthesizing a new concept that overcomes its weaknesses. Focus attention on the criteria with the lowest ratings for that concept (“1’s” and “2’s”). What changes can be made to the design or formulation of the preferred concept(s) to improve these low ratings with the product concept? Compare the preferred concept(s) to the other concepts that have higher ratings for that particular requirement. Are there ways to modify the preferred concept to incorporate the advantage of another concept?