The Challenge of Software Cost Estimation
for Long-Term Information Preservation of
Earth Science Data
Bruce R. Barkstrom
Asheville, NC
Paula L. Sidell
League 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 data
in 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



●
Accounting treatment of assets



●
Non-depreciable
Public good
Value arises from data use
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
Disasters
Human Health
Immediate Use
1-2 Yr Use
4-25 Yr Use
25-100 Yr Use
Doomsday Use
Warning
Energy
Climate
Water
Power Plant Siting
Mitigation and Adaptation
Infrastructure Planning
Weather
Ecology
Info Service
Agriculture
Oceans
Precision Ag Service
Fisheries Info Service
Process Studies
Biodiversity
Crop Insurance
The Accountant's View of Value
●
●
●
●
Accountants View an
Organization in terms
of the
Flow of Funds
A Basic Chart of Accounts
Debit
Assets [A]
not allowed in standard
rules of accounting
Fund Balance [F]
Liabilities [L]
Expenses [E]
Funds are placed in a
Chart of Accounts
Frequent changes in
the Chart of Accounts
are
Credit
Income [I]
Funding Balance
Requires
DA + DL = I – E
Or
Sum of Asset Changes
plus
Sum of Liability Changes
equals
Difference Between Income and
Expenses
Information Asset Valuation
Activity
Satellite Missions
Instrument Dev. [T]
Instrument Char. & Cal Facil. [T]
Instrument Char. & Cal. [I]
Instr.-Sat. Integration
Sat.-Vehicle Integration
Initial Sat./Instr. Checkout
Sat./Instr. Ops.
In Situ Data Networks
In Situ Data Site Dev. [T]
In Situ Data Site Ops.
Science Data Production
Science Algorithm Dev. [T]
Science Data Validation [I]
Science Data Production [T]
Science Data Prod. Facility [T]
Archival Activities
Archive Ingest [I]
Archive Curation [T]
Archive Facilities [T]
Archive Operations
User Access
Expected
Interval Accounting Account
[yr]
Basis
Type
5
5
0.2
0.5
0.5
0.2
LOM
M
F
M
M
M
M
F
DC
DC
O
O
O
O
O
2
LOM
M
F
HS
O
LOD
LOM
LOM
LOM
F
F
F
F
SD
O
O
HS
LOM
LOD
LOD
LOD
F
F
F
F
O
O
HS
O
●
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
Practical Asset Valuation
●
Three Standard Methods

Acquisition Cost
●

Replacement Cost
●

No possible replacement of lost observations
Net Present Value of Flow of Future Value
●
●
Ultimate Residual Cost attributable to investment in calibration,
data production, validation, and reprocessing
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 Cost
1. Identify threats
2. Estimate probability of loss and probable value
of loss if threat materializes
3. Develop affordable strategy to mitigate risk
The Challenges of Preservation
●
Stringent Requirements
Probability of Loss per Year, p
10.00% 1.00% 0.01%
Probability of Survival to Year 201 6.4 X 10-10 0.13
0.98
●
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
A Refined Balance Sheet
Debit
Assets
Data
Metadata
Documentation
Human Capital
General Assets
Buildings and Related Assets
Credit
Capitalization
Liabilities
IT Security Incidents
Loss of Context
Format and Software Obsolescence
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)