Measures of Effectiveness

Details on the Measures of Effectiveness (MOE) used in SpaceNet 1.3 are contained in Appendix D of the user manual:

SpaceNet User Manual: de Weck O.L., Simchi-Levi D., Shishko R., Ahn J., Gralla E., Klabjan D., Mellein J., Shull A., Siddiqi A., Bairstow B, Lee G., "SpaceNet v1.3 User's Guide", NASA/TP-2007-214725, January 2007

Any supply chain is a system, and as such, its design should involve comparing alternatives by objectively measuring how well each achieves the system's purpose. The space logistics simulator SpaceNet is a means for doing that for the interplanetary supply chain. A set of measures of effectiveness (MOEs) is currently available in SpaceNet (v.1.3 and 2). These fall into the following four categories:

• Basic Logistics Performance
• Exploration Capability and Relative Exploration Capability
• Relative Scenario Cost
• Scenario Risk

The MOEs defined in SpaceNet provide a quantitative way to evaluate specific space exploration scenarios and interplanetary supply chains in general. While we believe that these MOEs are important and relevant for space exploration logistics, they are only proxy metrics for comparative purposes, not for absolute forecasting.

Basic Logistics Performance MoEs

• Crew Surface Days [crew-days]
  • Total number of crew-days over all surface nodes for entire scenario
• Exploration Mass Delivered [kg]
  • Total mass of COS 6 and COS 8 delivered over all surface nodes for entire scenario
• Total Launch Mass [kg]
  • Total launch mass (including crew, elements, and all other COS) for entire scenario
• Upmass Capacity Utilization [0,1]
  • Fraction of upmass capacity (from Earth) used by COS (excluding crew, propellants, and elements) for entire scenario

Exploration Capability MoEs

• Exploration Capability [kg • crew-days]
  • Dot product of crew surface and exploration mass (COS 6 and COS 8) over all surface nodes for entire scenario
• Relative Exploration Capability [0, ∞)
  • Exploration capability Divisia index with Apollo 17 normalization
  • Practically, scenario exploration capability / scenario total launch mass relative to Apollo 17

Relative Scenario Cost MoEs

Relative Scenario Cost

Weighted sum of total launch mass and the number of element active days for entire scenario, using weights such that relative scenario cost for Apollo 17 = 1 Scenario Risk MoEs

Scenario Risk MoEs

Scenario Risk

1- Probability {no failures in all launches, rendezvous and dockings, and landings for entire scenario}