Conceptual Modeling of Human Processes in a Lunar Systems Architecture

This paper presents a case for supporting the architecting of a conceptual system and its associated human activity with an analytical model. The human activity is treated as a peer to the system's operation using Object Process Methodology (OPM) and uses manned Lunar operations as an example. There is a brief discussion of architecture, architecting, and systems architecture, to set the context for the terminology used to present the modeling context. This early stage analytical modeling in a systems conceptual definition provides a comprehensive means for evaluation of the design for functions it is required to support. The models also provide a consistent basis for the more complex models used later in the systems implementation. Systems modeling is an accepted practice for describing the complex interactions in and among systems, however, the modeling of human activity in conjunction with systems is less well developed. The Systems Modeling Language (SysML) is an accepted systems modeling capability that requires up to seven types of diagrams to represent a system and its operation. OPM is a more recent development in systems modeling and, in contrast to other methods, has a single diagramming methodology which can represent structure, dynamics and relationships. The OPM naturally represents human activity as an agent interacting with a system or as an object within the system. The NASA Lunar Architecture and a functional analysis of an Apollo based Lunar rover are used as a basis for the OPM models of crew activities. Models for humans as agents for a system, as well as a part of a system, are presented with their peer text descriptions.