Hard Disk Storage Deflation: Is There a Floor?
Storage system costs are a major component of many automated information systems (AIS) cost estimates. Vendor quotes or specific storage specifications are sometimes available to estimate the cost of these storage solutions, but often, especially for significantly future storage cost projections, a $/volume of storage is often applied to projected storage volumes. Storage costs historically deflate considerably over time; Cost Deflation vs. Technology Inflation of RAID (Redundant Array of Independent Disks) Storage Systems (Converse, Watkins, SCEA 2006) supports the claim that RAID storage costs deflate 30-40% per year. Using these deflation rates from year to year quickly leads to near zero $/volume costs for RAID storage. To counter near- zero $/volume costs, cost estimators sometimes choose to use a “floor” to this deflation. For estimates that go out past five to six years, the choice of the floor value becomes a significant input to the storage cost estimate.
This paper explores whether or not these “floors” exist, by examining historical RAID $/volume storage costs against current RAID values. This paper examines only $/volume costs. Future storage system requirements, including any additional storage needed to accommodate increased systems requirements or file sizes, should be correctly captured. Historical data at least seven years old is compared against current RAID costs; if floors to deflation exist, they would be evident in a data set of this length. The data set is modeled using an exponential curve with a linear y-intercept to account for the floor. The paper will also briefly discuss possible factors, such as significant storage medium changes and increased storage volumes; that may cause realized storage cost floors.
Laura M. Friese
Laura M. Friese is an Operations Research and Cost Analyst for Northrop Grumman, supporting Intelligence Community and DoD projects. For the past three years, she has focused on the development of Intelligence Capability Baseline Descriptions (ICBDs) and life-cycle cost estimates for Automated Information Systems for the Intelligence Community. She also has worked on Operating and Support Estimates for naval systems as well as Independent Cost Proposal Evaluations throughout Northrop Grumman. Ms. Friese is the author of Modeling Data with Distinct Zero and Non-Zero Cost Years (SCEA 2006). Laura holds a B.A. in Mathematics from the University of Virginia and a M.S.E. in Operations Research and Financial Engineering from Princeton University.
Allison L. Converse
Allison L. Converse is an Operations Research and Cost Analyst for Northrop Grumman. In the past, she has supported Statistics Northwest with research in data quality improvement. For the past three years, she has been primarily supporting the Intelligence Community on cost estimates and Intelligence Capability Baseline Descriptions (ICBDs) for Automated Information Systems. Ms. Converse is the author of Cost Deflation vs. Technology Inflation of RAID Storage Systems (SCEA 2006) and Software Schedule Realism Prediction Band Tool (SCEA 2007). Ms. Converse earned her B.S. in Mathematics with a Concentration in Operations Research and a Minor in Computational Finance from Carnegie Mellon University.
David A. Wiley
David A. Wiley has more than seven years experience as a cost analyst. Prior to coming to Northrop Grumman – TASC, Mr. Wiley spent two years working Department of Defense (DoD) projects most notably supporting the Missile Defense Agency (MDA) where he supported estimating efforts for various types of programs including radar, missile, and command, control, communications and intelligence (C3I) systems. Since joining TASC he has been heavily involved in Automated Information Systems cost estimating for both DoD and Intelligence Community customers. He also supports estimating efforts internal to Northrop Grumman providing Independent Cost Evaluations across multiple sectors of the company. Mr. Wiley is the author of ERP: An Emerging Paradigm (SCEA 2005).
Alisha M. Soles
Alisha M. Soles is an Operations Research Analyst for Northrop Grumman, supporting the Intelligence Community. For the past three years, she has primarily been involved in developing life-cycle cost estimates and Intelligence Capability Baseline Descriptions (ICBDs) for Automated Information Systems. Ms. Soles earned her B.S. in Business Management from Virginia Polytechnic Institute and State University.
Christopher C. Thomas
Christopher C. Thomas is an Operations Researcher for Northrop Grumman, primarily supporting Intelligence Community projects. For the past three years, he has focused on the development of Intelligence Capability Baseline Descriptions (ICBDs), life-cycle cost estimates, and automated cost analysis tools for Automated Information Systems. Mr. Thomas also serves as a Technical and Research lead within Northrop Grumman TASC. He holds a B.S. in Industrial Engineering from North Carolina State University and is pursuing a Masters in Systems Engineering from the University of Virginia.