Time: 4pm, Tuesday December 5
Place: Room 110, South Hall


                    Modeling and Simulating Work Practice
                         Maarten Sierhuis, NASA Ames

Representing how people do work can be done at many different levels. In the knowledge 
engineering and AI world, people's work has been described in terms of their 
problem-solving expertise. There, the theory is that we can model people's 
problem-solving behavior by representing this behavior in a computational model that 
is able to duplicate some of this behavior. Work process models, such as Petri-Net 
models of a work process, describe what tasks are performed and when. In workflow 
models we describe how a specific product "flows" through an organization's work 
process. This describes the sequential tasks in the work process that "touch" a 
work-product. All these modeling approaches describe the work in a system at a certain 
level of detail. However, what is missing from all these types of modeling approaches 
is a representation of how work gets done. What is missing is a description of the work 
at the work practice level. Work practice includes those aspects of the work process 
that make people behave a certain way in a specific situation, and at a specific moment 
in time. To describe people's situation-specific behavior we need to include those 
aspects of the situation that explain the influence on the activity behavior of 
individuals (in contrast with problem-solving behavior), such as: situated activities, 
agent's beliefs, world facts, tools and artifacts, geography, situational effects on 
the activities, communication between agents and the use of communication tools, and 
agent reasoning.

Brahms is a tool for modeling and simulating the way people work and collaborate, and 
use systems to accomplish their tasks. Brahms can be used to describe current and 
future work processes and practices in human and other types of organizations. Another 
application of Brahms is to design the collaborative activities between multiple 
intelligent agents-human- and software agents.
Brahms consists of a number of tools to develop simulation models of the activities 
and collaboration of multiple agents:
· A multi-agent modeling language for modeling agents.
· A multi-agent discrete-event simulation engine for executing (i.e. simulating) Brahms 
  models.
· A relational simulation history database for capturing the data from a simulation for 
  later analysis.
· A multi-agent time-line view of the activities of agents, including the communication 
  interaction between agents.

With Brahms we can model and simulate how people and systems work and interact. There are 
many tools and languages for describing and designing the formal specification of system 
behavior. However, there are not many systems that are able to describe the intelligent 
and social behavior of humans, as well as the cooperative and collaborative behavior 
between humans and systems, and the situational interaction with the environment. The 
Brahms environment includes aspects of human and system behavior and interaction. This 
means that with Brahms we can model and simulate how things happen in the real world. 
With Brahms it is possible to use a formal modeling and simulation approach as an analysis 
and design methodology in the development of Cooperative Multi-Agent Systems.

In this seminar, I will cover some of the theoretical underpinnings of Brahms, as well as 
explain some of its representational capabilities, by using an example from my 
Human-Centered Computing research at NASA Ames Research Center. I will talk about my 
efforts in modeling and simulating how the Apollo Astronauts worked on the Moon, and how 
we intend to use Brahms for designing a work practice for human-robotic collaboration in 
future robotic missions.