Toward a Method for Achieving Synergy between Heuristic Rules of Thumb and Quantitative Methods in Engineering Design

工程设计专家的启发式“经验法则”通常在做设计决策时节省时间和金钱。通过多年的产品设计、材料和制造经验，专家可以快速执行许多设计任务，例如缩小可能的设计选项集以进一步研究。然而，有时候，这些捷径会导致糟糕的设计决策，浪费时间和金钱。这种情况尤其发生在考虑新材料、制造技术或产品类型的时候。旧的经验法则不再适用，即使是专家也可能容易受到“认知偏见”的影响，或者我们有时都会陷入的决策陷阱。尽管数学模型和方法可以缓解这个问题，但它们通常需要大量的成本和努力来实现，因此会抵消预期的好处。这个项目将通过结合两个世界的优点来造福社会，致力于确定快速启发式策略和更严格的定量方法之间的最佳平衡，以做出设计决策。这个项目的智力意义在于为一种新的、正式的设计方法建立基础，这种方法利用了启发式和规范性方法之间的协同作用。这个项目将分析一个高级系统工程问题的设计过程，设计师需要扩展分析框架，包括以前从未考虑过的问题。诸如优化和基于决策的设计等规范方法考虑了不确定性下的效率和权衡，其分析严密性与以前仅应用于物理系统建模的程度相同。虽然这种方法在某种程度上是成功的，但有时这种方法的成本（制定、收集数据、解决问题）根本不值得付出努力。相反，设计专家使用的启发式“经验法则”更快，但有时会导致次优结果，因为系统的认知偏差无意中嵌入在启发式中，导致设计选择远离最优解决方案。这里要解决的问题是，严格的启发式设计方法可能导致较差的解决方案，而严格的规范方法可能过于耗时和昂贵而无法实现。将分析观察到的启发式，以确定它们对设计过程和最终产品的影响。规范性方法将以同样的方式进行分析。然后，将开发一种确定两种方法最佳组合的方法。这个项目将为开发一套完整的“理性设计分析规则”提供基础，以确定规范和启发式方法的最佳组合。

Engineering design experts' heuristic "rules of thumb" usually save time and money when making design decisions. Through years of experience with product design, materials, and manufacturing, experts can perform many design tasks quickly, such as narrowing the set of possible design options to investigate further. Sometimes, however, these shortcuts result in poor design decisions that waste time and money. This happens especially when new materials, manufacturing technologies, or types of products are being considered. The old rules of thumb no longer apply, and even experts can be vulnerable to "cognitive biases," or decision traps that we all sometimes fall into. Although mathematical models and approaches can alleviate this problem, they often require significant cost and effort to implement and therefore counteract the desired benefit. This project will benefit society by combining the best of both worlds, working toward a methodology for determining the best balance between rapid heuristic strategies and more rigorous quantitative methods for making design decisions. The intellectual significance of this project lies in building a foundation for a new, formal design methodology that exploits the synergy between heuristic and normative methods. This project will analyze a design process for one advanced systems engineering problem, where the designer is required to expand the frame of analysis to include issues never before considered. Normative methods such as optimization and decision-based design consider efficiency and tradeoffs under uncertainty with the same degree of analytic rigor that was previously applied only to physical system modeling. While this approach has been successful to some extent, there are times when the cost of this approach (formulation, data gathering, solving) is simply not worth the effort. Conversely, the heuristic "rules of thumb" employed by design experts are faster, but can sometimes lead to suboptimal results because of systematic cognitive biases that are inadvertently embedded in the heuristic and lead the design choice away from the optimal solution. The problem addressed here is that strictly heuristic design methods can lead to inferior solutions, while strictly normative methods can be too time consuming and costly to implement. Observed heuristics will be analyzed to determine their effect on both the design process and the resulting product. Normative methods will be analyzed in the same manner. Then, a method for defining the best combination of the two approaches will be developed. This project will provide the foundation for developing a full set of "rules for rational design analysis" for determining the best combination of normative and heuristic approaches.