Revisiting the Tradespace Exploration Paradigm: Structuring the Exploration Process

Abstract

A number of case applications of tradespace exploration have further extended the types of analyses and knowledge insights that can be gained about tradeoffs between design choices and perceived utility and cost of alternatives. These extensions include application beyond its heritage aerospace domain to the transportation domain, comparing distinct concepts on a common tradespace, considering the impact of changing needs and contexts over time, evaluation of alternatives in a "light effort" manner. In parallel with these case applications, a formalization of the tradespace exploration process has emerged, using a question-driven approach to ensure the knowledge generated is practical and useful to decision makers. These questions are introduced and applied to three example space systems in order to illustrate insights gained in answering the questions. The insights include identifying "good" designs, the strengths and weakness of selected alternatives across a tradespace, limiting constraints and requirements that could allow for less expensive solutions. Additionally, advanced insights include understanding the sensitivities of designs to changes in contexts and needs, and consideration of the differential impact of uncertainty across a set of alternatives with potential opportunities for risk mitigation.

Multi-Epoch Analysis of a Satellite Constellation to Identify Value Robust Deployment across Uncertain Futures

“…Since Pareto Trace operates across epochs, it provides a method to identify designs that are passively value robust. Comparing the characteristics of designs with a high Pareto Trace gives insight into which design variables most impact system value across alternative future contexts 15 .…”

Role for Interactive Tradespace Exploration in Multi- Stakeholder Negotiations

“…After the preference sets are specified, each stakeholder needs to use the methods of basic tradespace exploration 19 to find a set of favored designs. In addition to forming the starting point for negotiations, this step allows the stakeholders to understand the nature of the tradespace, the characteristics of their favored solutions, and some of the trades that they might have to make, even acting alone without the complication of considering the other stakeholders.…”

“…A tradespace, for the purposes of this paper, is represented by a data set (computed ahead of time) that includes a large number of possible designs, and their analyzed performances. 18,19 The designs are expressed parametrically by varying the elements of a design vector. The performance is expressed in terms of attributes, metrics of interest to, and chosen by, the stakeholders.…”

“…This usage, instead, emerged as a stakeholder-identified promising approach over the course of maturing tradespace exploration techniques in general. 19 A more targeted research effort that develops tools, representations, and techniques to streamline the steps suggested in this paper, including the ability to readily track impacts of negotiations, such as "lost utility" and "extra cost incurred" due to compromises can help to make explicit fundamental tensions and tradeoffs that inherently exist in multi-attribute, multi-stakeholder design problems.…”

A Method for Exploring Program and Portfolio Affordability Tradeoffs Under Uncertainty Using Epoch-Era Analysis: A Case Application to Carrier Strike Group Design

“…A recently developed approach, ^Åèìáëáíáçå=oÉëÉ~êÅÜ=mêçÖê~ãW= êÉ~íáåÖ=póåÉêÖó=Ñçê=fåÑçêãÉÇ=`Ü~åÖÉ= -202 -Epoch-Era Analysis (EEA), enables the conceptual design of systems that are resilient to potential changes in context and needs (exogenous uncertainties) over the lifecycle of the system. EEA enables quantitative support for the design of particular time-contingent system properties such as survivability, flexibility, and affordability (Ross et al, 2010).…”