Question

The weight assignments of the evaluation criteria can be subjective by the stakeholder of the criterion (or criteria). Use an example to demonstrate that the sensitivity of weight assignments dominates the outcome of trade studies. How the QFD can help the objective selection of weight assignments of evaluation criteria?

Please answer in detail ( one to two page answer)

Answer 1

Quality Function Deployment (QFD) is a process and set of tools used to effectively define customer requirements and convert them into detailed engineering specifications and plans to produce the products that fulfill those requirements. QFD is used to translate customer requirements (or VOC) into measureable design targets and drive them from the assembly level down through the sub-assembly, component and production process levels. QFD methodology provides a defined set of matrices utilized to facilitate this progression.

ü The definitions of measures and measurement methods for system effectiveness, system performance, and system cost are related to the definition of goals and objectives and Functional Analysis performance. These measurements are the decision criteria. Each quantitative measure shall have a defined measurement or computational method. This task initiates the analytical portion of the Trade Studies process, as it involves using quantitative methods.

ü The definition of evaluation criteria requires considerable engineering judgment and interaction with the stakeholder to establish the appropriate criteria, associated weights, and scoring methods. For example, supporting missions with tight schedules requires heavy weighting of schedule risk, while supporting missions with more flexible schedules generally emphasizes low cost while accepting higher schedule risks. Sufficient comments shall be provided for each evaluation criterion to ensure evaluator and stakeholder comprehension. Stakeholder approval shall be obtained before proceeding to the next task

ü The technical requirements that potential solutions need to achieve serve as the criteria against which alternative concepts are measured. The selected criteria may include limits of minimum acceptable values and desirable attributes that permit judging of candidates against each other. Trade Studies leaders are encouraged to use Quality Function Deployment (QFD) to help to define the evaluation criteria and weighting factors applicable to the Trade Studies. These criteria are defined based on the technical requirements that determine if a design is acceptable to the Stakeholder Needs.

ü Evaluation criteria are more meaningful if they represent measurable characteristics, which is not always possible. It is recommended that criteria on cost and risk be included. Alternatives may be evaluated based on projected fixed and variable cost using risk factors, when applicable, to derive expected costs. It is also recommended that elements not directly related to cost (e.g., weight, production cycle time) have criteria established to associate cost with changes in the elements. Trade Studies shall address these criteria.

ü Evaluation criteria that apply specifically to the Trade Studies shall be selected, adding additional relevant criteria, such as security, as needed. For each evaluation criterion, established threshold values that may be used to evaluate the alternatives on a pass/fail basis shall be identified. An example criterion is: “The system MTBF shall be 10,000 hours or greater." For the remaining criteria, a weight and scoring range shall be assigned for use with the weighted matrix evaluation method. Criteria are ranked and grouped into three categories so that the assigned weights reflect their criticality. The most critical criteria are assigned large weights and flagged so that any alternative with low scores for these criteria influence any subsequent analysis. Mid-critical and noncritical criteria are assigned smaller weights; it is recommended that noncritical criteria have a negligible effect in further analysis.