Galaxy Charts: The 1,000-Light-Year View of the Data
Methods and Models I Track
The old adage “A picture is worth a thousand words” is one that we have all heard and often try to use to our advantage. This paper applies the principles of visual display of information as advocated by Edward Tufte and others to develop an innovative graphic that will prove invaluable to cost estimators and consumers of their estimates everywhere.
Pictures, graphs, charts, and tables are common throughout analysis and documentation efforts of all sorts, and cost estimates are no exception. In fact, data visualization and new ways to depict data are increasingly important in both the conduct of analysis and its presentation to decision-makers. Many analysts use graphs to better understand their data, display results, and cross-check findings.
It has been a particular challenge to display data housed in a hierarchical Work Breakdown Structure (WBS), as are most cost estimates. The difficulty arises because there are usually varying levels of detail that are related. Analysts often examine costs elements or levels one at a time. This often leads to “tunnel vision” on a piece of the life cycle cost estimate (LCCE) that may be rather inconsequential in the comprehensive view of the estimate. Though data visualization techniques such as pie charts and Pareto charts can go a long way in helping an analyst see what is important, it is often easy to focus on one slide while forgetting the rest of the brief or, in other words, to lose sight of the sky when focusing on one star.
This paper presents a new kind of chart, called a Galaxy Chart, which is specifically designed to display data in any type of WBS. A Galaxy Chart can display an entire WBS on a single sheet of paper, showing all WBS elements, relationships, costs, and even methodologies in a visual way. Each child cost element is “in orbit” around its parent, with its children (i.e., grandchildren) “in orbit” around their parent. The size of each element is directly proportional to its cost (and hence importance). Many insights can be gained in a single view with this information-dense chart. For example, when the cost element you’ve been obsessing over turns up, small and remote like Pluto, you are gently reminded to focus on the Jupiter and Saturn cost elements first! This paper will give an overview of the Galaxy Chart, explain how to construct it, and go over a few of the insights that can be gained from this display, insights that are typically difficult to gain without it. It will discuss multiple variants and present many examples.
Mr. Nehring is a cost analyst for Technomics, where he has been involved on many projects throughout the Department of Defense (DoD), including the Army, Navy, Coast Guard, and Marine Corps. Early in his career, Mr. Nehring supported the Office of Naval Research by leading a project that analyzed and assessed the schedule and staffing projections for the Navy’s Littoral Combat Ship (LCS). Once joining Technomics, he has provided cost support to many programs including LCS, Ohio Replacement Program, Capabilities Knowledge Base, and others. In addition, he has been heavily involved in building both submarine and surface combatant performance based cost models for the Navy. Currently, he primarily supports the Coast Guard Offshore Patrol Cutter, the Navy’s Visibility and Management of Operating and Support Cost (VAMOSC) database, and the OSD CAPE in the Cost Assessment Productivity Project. Mr. Nehring holds both undergraduate and graduate degrees in Industrial and Systems Engineering from Virginia Tech and is a SCEA-Certified Cost Estimator/Analyst (CCEA).
Ms. Kammy Mann is a cost analyst for Technomics, Inc. where she has been involved on projects throughout the Department of Defense. During her career she has supported the Deputy Assistant Secretary of the Army-Cost & Economics (DASA-CE), Naval Sea Systems Command (NAVSEA), Naval Surface Warfare Center Carderock, and Defense Acquisition University (DAU). Ms. Manns experience supporting these customers includes applied cost analysis and research, relational database maintenance, developing and enhancing an analogy model using non-recurring engineering data, and assisting with training modules on software cost estimating. Before joining Technomics she worked as an Industrial Engineer for Altec Industries where she provided lean manufacturing support to the crane production line and was the Director of Undergraduate Recruiting for the College of Engineering at Virginia Tech. Ms. Mann holds both Bachelors and Masters of Science in Industrial and Systems Engineering from Virginia Tech as well as a graduate certificate in Engineering Education.
Robert R. Jones
Mr. Robert R. Jones graduated from the University of Rhode Island with a Bachelors degree in Mechanical Engineering in 1969, and he received a Masters degree in Mechanical Engineering from the Catholic University of America in 1973. For thirty-three years he was employed by the Navy at the NSWC Carderock Division. In January 2003, when he retired from the Navy, he was the Department Head of the Systems Engineering and Analysis Department. Since 2003, he has been a Senior Cost Analyst with Technomics, Inc. Mr. Jones has thirty years of experience in cost estimating and economic analysis for the development, production, and operations and support of Navy technologies and systems; software cost estimating and cost model development; support for ACAT I program offices, including earned value management analysis; preparing Independent Cost Estimates; participating in source selections; support for OSD cost and software data reporting activities, and performing applied research in a variety of cost analysis fields.