Collaborative Research: Exploring the Evolution of Design Requirements Throughout the Design Process Using Network Models

所有的设计问题都受到一组必须在项目交付时得到满足的需求的约束。然而，需求会随着项目持续时间的变化而变化，从而导致“移动目标现象”，并危及项目的成功。需求的变化可能由于技术、消费者趋势、观念或法规的变化而发生。在需要数年时间进行设计和制造的复杂系统中，或者那些包含成千上万个需求的系统中，这种需求的不稳定性尤为重要。研究表明，在美国，超过一半的失败项目是由于需求及其管理方面的失败而发生的，这阻碍了市场成功、创新和工程追求。这项研究的目标是了解需求是如何变化的，更重要的是，它们对设计的其他元素的影响。尽管工程师可能会考虑需求变更的影响，但很难处理它如何影响其他几个需求或系统组件。了解需求如何变化，以及它们对设计过程中其他元素的影响，可能会改变我们在整个设计过程中设计和利用需求的方式。尽管需求构成了每个工程项目的支柱，但是分析需求所需的正式推理支持是有限的。在设计的早期（启发）和后期（满足）阶段之外理解它们的使用有助于理解中间阶段发生的事情，这是一个认识到但尚未得到很好理解的不稳定过程。本研究的目的是促进对系统设计中工程需求演变的基本理解。这项研究解决了在描述和规定工程师如何使用，更重要的是，如何在整个设计过程中使用需求方面的差距。具体的探索将集中于测量和预测需求的不稳定性。为此，本研究将对现有的需求变更传播预测方法进行改进，以纳入测量波动性所需的图论度量。定量和定性数据都是在为期三年的多案例研究中收集的，该研究跨越了来自不同设计项目的2760个不同需求文档。将分析需求及其变更数据，以确定是否可以使用易变性度量来理解需求是如何演变的。这项研究将使工程师能够在设计过程的早期分析需求，以评估与其他需求相关的单个需求的波动性。通过允许工程师和设计师在提交更改之前分析更改传播和影响，这为设计过程增加了价值。

All design problems are constrained by a set of requirements that must be satisfied at project delivery. However, requirements change over the span of a project's duration, causing the "moving target phenomenon," and jeopardizing the success of the project. Changes in requirements may occur due to changes in technology, consumer trends, perceptions, or regulations. Such requirements volatility is particularly important in complex systems that require several years for design and manufacturing or those that contain tens of thousands of requirements. Research has shown that over half of failed projects occurred due to failure stemming from requirements and their management, hindering market success, innovation, and engineering pursuits in the United States. The goal of this research is to understand how requirements change, and more importantly, their effect on other elements of design. Whereas an engineer may consider the impact of a requirement change, it is difficult to process how this may affect several other requirements or system components. Understanding how requirements change, and their effect on other elements of the design process may change how we design and utilize requirements throughout the design process.Although requirements form the backbone of every engineering project, the formal reasoning support needed to analyze requirements is limited. Understanding their use outside of the early (elicitation) and late (satisfying) phases of design can contribute to understanding what happens in the interim, a volatile process recognized yet not well understood. The objective of this research is to advance the fundamental understanding of engineering requirements evolution within systems design. This research addresses a gap in both describing and prescribing how engineers use and, more importantly, could use requirements throughout the design process. A specific exploration will focus on measuring and then predicting requirements volatility. To this end, this research will enhance an existing Requirement Change Propagation Prediction Method to incorporate graph theoretic metrics needed to measure volatility. Both quantitative and qualitative data is collected during a three-year, multi-case study spanning 2,760 different requirements documents from varying design projects. Requirements and their change data will be analyzed to determine if volatility metrics could be used to understand how requirements evolve. This research will enable engineers to analyze requirements early in the design process to assess the volatility of individual requirements as they relate to other requirements. This adds value to the design process by allowing engineers and designers a means to analyze change propagation and impact before committing to changes.