The Challenge of Software Cost Estimation for Long-Term Information Preservation of

Earth Science Data

Bruce R. BarkstromAsheville, NC

Paula L. SidellLeague City, TX

Outline

● The Accountant's View of Earth Science Data

● Information Preservation Threats create contingent liabilities that are

needed to prevent asset impairments● The Role of Software Development in Earth

Science Information Accounting● Cost Modeling

The necessity for economy in information preservation

An interesting factor: the cost of control

Basic Accounting Questions

● Key Question:What value should the government

carry on its books for Earth science datain its archives?

● Accountant Answers:1. Use “market value” - but Earth science data is a public

good, without a market (except maybe high resolution imagery)

2. Use “cost of reproduction” - but Earth science data is not “reproducible” - if you miss it, it's gone

3. Use “Net Present Value of stream of future benefits” - but science data value likely not just economic

An Accounting View of the Value of Earth Science Data

● Earth science data appears to fall into the category of “cultural, artistic, and scientific” asset Non-depreciable Public good Value arises from data use

● Accounting treatment of assets Launch vehicles, satellites, and instruments are “equipment

costs” - “sunk expenses” at end of life Some “operating expenses” may be viewed as “insurance

against value impairment” Direct cost of software to interpret data and for activities of cal

and val are readily measured● Earth Science Data Value represents the cost of the

investment in making the data useful

Data Uses for Societal Benefits

● USGEO (and related programs) have identified 9 societal benefit areas

● Data Uses usefully divided by time scale of required observation period (sample uses)

USGEO Societal Benefit Area Immediate Use 1- 2 Yr Use 4- 25 Yr Use 25- 100 Yr Use Doomsday Use

Disasters Warning

Human Health

Energy Power Plant Siting

Climate Mitigation and Adaptation

Water Infrastructure Planning

Weather Info Service Process Studies

Ecology Biodiversity

Agriculture Precision Ag Service Crop Insurance

Oceans Fisheries Info Service

The Accountant's View of Value

● Accountants View an Organization in terms of the Flow of Funds

● Funds are placed in a Chart of Accounts

● Frequent changes in the Chart of Accounts are

● not allowed in standard rules of accounting

A Basic Chart of Accounts

Debit Credit

Assets [A] Fund Balance [F]

Liabilities [L]

Expenses [E] I ncome [I ]

Funding Balance Requires

DA + DL = I – E

Or

Sum of Asset Changes plusSum of Liability Changes equalsDifference Between Income and Expenses

Information Asset Valuation

● For Activity● T: Activity produces a Tangible asset, such as hardware,

software source code, or documentation● I: Activity produces an Intangible asset, primarily

information that may be used by researchers, decision makers, or other data users

● For Expected Interval● LOM: Life Of Mission, which may be taken as ten years for

a single satellite or instrument, and which may increase to more than a century for operational environmental observation capability

● LOD: Life Of Data, which NARA defines as 75 years beyond scientific research use. Here, we take this time period to be 200 years – give or take

● For Accounting Basis● M: Modified Accrual accounting basis● F: Full Accrual accounting basis● For Account Type● DC: Development and Construction● O: Operations● HS: Hardware and Software, including accounts for initial

capitalization, depreciation, and refresh/upgrades● SD: Specialized scientific software Development

Activity

Satellite MissionsInstrument Dev. [T] 5 M DCInstrument Char. & Cal Facil. [T] 5 F DCInstrument Char. & Cal. [I] 0.2 M OInstr.-Sat. Integration 0.5 M OSat.-Vehicle Integration 0.5 M OInitial Sat./Instr. Checkout 0.2 M OSat./Instr. Ops. LOM F O

In Situ Data NetworksIn Situ Data Site Dev. [T] 2 M HSIn Situ Data Site Ops. LOM F O

Science Data ProductionScience Algorithm Dev. [T] LOD F SDScience Data Validation [I] LOM F OScience Data Production [T] LOM F OScience Data Prod. Facility [T] LOM F HS

Archival ActivitiesArchive Ingest [I] LOM F OArchive Curation [T] LOD F OArchive Facilities [T] LOD F HSArchive Operations LOD F O

User Access

Expected Interval

[yr]Accounting

BasisAccount

Type

Practical Asset Valuation

● Three Standard Methods Acquisition Cost

● Ultimate Residual Cost attributable to investment in calibration, data production, validation, and reprocessing

Replacement Cost● No possible replacement of lost observations

Net Present Value of Flow of Future Value● Non-economic nature of data use of a public good makes

method moot

● Common-Sense Approach Use of data must be timely, relevant, and reliable Value of data based on cost of expert interpretation as

embedded in software and cal-val cost

Expense Accounts

● Non-depreciable Asset subject to Asset Impairment Equivalent to buying insurance to reduce loss of

value due to asset impairment

● Standard Approach to Insurance Cost1. Identify threats2. Estimate probability of loss and probable value

of loss if threat materializes3. Develop affordable strategy to mitigate risk

The Challenges of Preservation

● Stringent Requirements

● Potential Loss Mechanisms Institutional instability and funding flow changes Operator errors Media, hardware, and software errors Loss of context, including software obsolescence IT security incidents with loss of user trust Evolution of hardware and software

10.00% 1.00% 0.01%Probability of Survival to Year 201 0.13 0.98Probability of Loss per Year, p

6.4 X 10-10

A Refined Balance Sheet

Debit CreditAssets Capitalization Data Metadata Liabilities Documentation IT Security Incidents Human Capital Loss of Context General Assets Format and Software Obsolescence Buildings and Related Assets

Expenses [offsets to avoid asset impairment] Income Replication (between agencies and governments) Operator Training and Monitoring Automation and Automation Testing Hardware Evolution Software Evolution Power and Air Conditioning Preservation Planning Administration

The Role of Cost Modeling

● Three Eras in an Earth Science Data Collection: Science Software Development Production and Validation Archive Preservation Management

● Three Kinds of Cost Modeling Challenges In 1st phase: Initial Ignorance In 2nd phase: Unplannable and uncontrollable activities In 3rd phase: Level of effort with minimum cost

Contingency Management

● Working Hypothesis: Unplannable and uncontrollable activities arise

because of● Initial ignorance (finite number of bugs)● Changes in environment (long-term = Annual Change

Traffic in classic COCOMO) Unplannable and uncontrollable activities create

need for resource contingencies● Approaches to Contingency Management

Squeeze out unplannable and uncontrollable activities = Waterfall Lifecycle

Reduce time in discovery-fix development-fix deployment = Agile Lifecycle

The Cost of Control

● Attempting to “Squeeze Out” Uncertainty Incurs Control Costs Education (inculcate “right behavior” through training) Communication (staff meetings as “consensus builder”) Enforcement (hiring and firing costs)

● Choice of Lifecycle Rationale: balance control costs against benefits of approach Probable optimal strategies:

● Low likelihood of unplannable and uncontrollable activities – use Waterfall (concentrate on control)

● Moderate liklihood of unplannable and uncontrollable activities– use Spiral (balance control costs against contingency costs)

● High likelihood of unplannable and uncontrollable activities – use Agile (concentrate on rapid discovery and removal of contingencies)