Keith Swanson

Semanticorganizer: a customizable semantic repository for distributed NASA project teams

Semantic Organizer is a collaborative knowledge management system designed to support distributed NASA projects, including multidisciplinary teams of scientists, engineers, and accident investigators. The system provides a customizable, semantically structured information repository that stores work products relevant to multiple projects of differing types. Semantic Organizer is one of the earliest and largest semantic web applications deployed at NASA to date, and has been used in varying contexts ranging from the investigation of Space Shuttle Columbias accident to the search for life on other planets. Although the underlying repository employs a single unified ontology, access control and ontology customization mechanisms make the repository contents appear different for each project team. This paper describes Semantic Organizer, its customization facilities, and a sampling of its applications. The paper also summarizes some key lessons learned from building and fielding a successful semantic web application across a wide-ranging set of domains with disparate users.

Earned Value Management at NASA: An Integrated, Lightweight Solution

This paper describes a fresh approach to earned value management (EVM) at the U.S. National Aeronautics and Space Administration (NASA). The goal of this approach is to provide a lightweight tool that allows project managers to apply earned value performance measurements with minimal effort in terms of data entry, and without the need to learn the highly specialized jargon that mystifies many EVM solutions. The presented technical and managerial solution addresses the practical challenges of applying EVM in the messy realm of project management. An empirical case study involving five projects at the NASA Ames Research Center illustrates the challenges of creating a consistent performance measurement baseline under the constraints of schedule, budget, and labor requirements, and of matching actual costs with budgeted costs on the level of granularity needed. The case study also highlights the benefits of using the implemented EVM solution in terms of data quality and time savings. The paper concludes with general recommendations for the design and application of EVM tools with the focus on ease of use.

Just-in-case scheduling for automatic telescopes

It is commonly acknowledged that there is a tradeoff between schedule quality and schedule robustness. In general terms, schedules that are of high quality tend to be of low robustness, and schedules that are robust tend to be of low quality. To better manage the robustness/quality tradeoff, we have developed an algorithm that implements what we call Just-In-Case scheduling; this algorithm explicitly considers the way in which scheduled actions might fail and how such failures can impact the executability of a schedule. Just-In-Case scheduling is able to build schedules that are robust and of high quality. The Just-In-Case algorithm is motivated in this paper by a specific telescope scheduling problem, and the paper presents the results of an experiment, carried out using real telescope scheduling data, that illustrates the performance improvement one can expect from using it.