Simulation Assumption Standard - (SAS)
OOF™ Origin Open Foundation™
Independent Methodological Authority
Operational Layer: Simulation Assumption Governance Layer
Category: Governance & Enforcement
Subcategory: Simulation Governance
Type: Parent Standard
Governed Space: Simulation Assumptions
Version: 1.0
Status: Canonical · Open Standard
Effective Date: 17 August 2026
Compatibility: OOF® Methodology OS™ · GOA™ · ORA™ · VALIDOS® · INTEGROS® · ADIT® · AGA™ ·
AIG® · CLIA® · MGIA™ · ASGA™ · RIS™
AI-Readable: Yes
Authority: OOF®
Protection: MIP® — Methodological Intellectual Property
Canonical Language: English (UCL™)
Governed Space
Simulation Assumptions
Canonical Definition
Simulation Assumption Standard (SAS) defines the governance conditions underwhich assumptions necessary to construct, configure, execute, interpret, or
maintain a simulation are explicitly identified, justified, bounded, related
to their supporting basis, connected to their dependencies, assessed for
uncertainty, constrained by their limitations, and preserved as traceable
components of the simulation lifecycle.
SAS ensures that simulation behavior, outputs, and downstream conclusions
cannot silently depend upon assumptions whose existence, basis, uncertainty,
dependency, or consequence remains unknown.
Purpose
Simulation cannot operate without assumptions.Some assumptions are explicit.
Others emerge from: incomplete knowledge, simplified reality, missing data,
uncertain environments, unresolved behavior, unavailable measurements, model
boundaries, computational constraints, or necessary approximations.
Assumptions may concern: physical conditions, system behavior, human behavior,
autonomous behavior, environmental conditions, dependencies, parameters,
distributions, operating conditions, boundary behavior, failure conditions, or
future states.
The purpose of SAS is not to eliminate assumptions.
The purpose is to make them governable.
Operational Role
SAS is the fourth Parent Standard of SIMULOS® — Simulation GovernanceArchitecture.
The preceding standards establish:
SOS — What exactly is being simulated?
SPSS — Why is it being simulated, what must it cover, and within which
boundaries?
RRS — Which aspects of reality must be represented, at what abstraction,
fidelity, resolution, and limitation?
SAS asks:
Which conditions must now be assumed so that this governed representation can
become an executable simulation, and what risks or interpretive limits do
those assumptions introduce?
SAS creates the methodological bridge between:
Governed Reality Representation
and:Simulation Model & Environment construction.
Governance Flow
Reality Representation Basis → Assumption Need → Assumption Identification →Assumption Basis → Assumption Dependency → Assumption Uncertainty → Assumption
Limitation → Assumption Consequence → Governed Simulation Assumption Basis
The resulting Simulation Assumption Basis becomes an input to:
Simulation Model & Environment Governance
Simulation Assumption
A Simulation Assumption is an explicitly or implicitly adopted conditiontreated as sufficiently true, stable, representative, bounded, or usable for
purposes of the simulation despite incomplete direct knowledge or complete
representation.
An assumption may define: what is held constant, what is presumed, what is
simplified, what is treated as representative, what relationship is expected
to hold, what behavior is presumed, what dependency is expected to remain
available, what uncertainty is bounded, or what condition is accepted for
simulation purposes.
Assumption ≠ Fact
SIMULOS® establishes:Simulation Assumption ≠ Established Fact
An assumption may be reasonable, evidence-supported, conventional,conservative, provisional, or necessary.
It must not silently become represented as independently established reality
merely because the simulation depends upon it. Assumption ≠ Reality
Representation
Reality Representation establishes how selected reality is represented.
Simulation Assumptions establish what must be presumed in order for that
representation and subsequent simulation to function.
For example:
Represented Weather System
belongs to Reality Representation.Weather remains within defined range X
during the scenario
may be a Simulation Assumption.The distinction must remain explicit.
Assumption ≠ Input
An assumption and an input may appear technically similar.However:
Input provides a value, dataset, signal, or condition to simulation execution.
Assumption establishes the governing premise under which that value or
condition is treated as usable or meaningful.
For example:
Input: Temperature = 25°C
Assumption: Ambient temperature remains approximately stable during thesimulated event.
The two concepts should not be collapsed.
Assumption ≠ Parameter
A parameter controls or characterizes the simulation model or environment.An assumption may determine why that parameter has a particular value, range,
distribution, or behavior.
Parameterization belongs to the subsequent Model & Environment governance
space.
SAS governs the assumption behind or around that parameter where relevant.
Explicit Assumption
An Explicit Simulation Assumption is formally identified and documented.Explicit assumptions provide a stronger governance basis because they can be:
reviewed, challenged, traced, tested, changed, or bounded.
Implicit Assumption
An Implicit Simulation Assumption exists where the simulation depends upon apremise that has not been formally declared.
Implicit assumptions may arise through: default settings, inherited models,
software conventions, engineering habits, undocumented parameter choices,
assumed independence, assumed stationarity, assumed user behavior, or
unchallenged historical practices.
SAS seeks to convert materially relevant implicit assumptions into explicit
governed assumptions.
Hidden Assumption
A Hidden Assumption is a materially relevant premise upon which simulationbehavior depends but whose existence is not visible to downstream users or
reviewers.
Hidden assumptions are methodologically dangerous because simulation outputs
may appear to arise from the model alone when they actually depend upon
undisclosed premises.
Assumption Identification
Assumption governance begins by asking:What must be presumed for this simulation to operate as designed?
Potential assumptions should be sought across: Simulation Object, Scope,
Reality Representation, model behavior, environment, parameters, inputs,
scenarios, dependencies, actors, interactions, timing, failure behavior, and
output interpretation.
Assumption Necessity
Not every uncertain condition must become an assumption.A condition becomes assumption-relevant where the simulation must treat it in
some defined way despite incomplete certainty or direct representation.
Assumption Basis
Every material Simulation Assumption should have an identifiable AssumptionBasis where possible.
The basis may derive from: observed operational data, historical behavior,
empirical evidence, engineering knowledge, physical principles, scientific
literature, expert judgment, design specifications, prior simulation,
validated domain models, contractual conditions, regulatory requirements,
conservative convention, or another documented source.
No Basis ≠ Invalid by Default
A simulation may sometimes require an assumption despite weak or unavailablesupporting basis.
SAS does not prohibit this.
Instead, the assumption should be classified accordingly and its uncertainty
and limitation strengthened.
Assumption Strength
Assumptions may vary in methodological strength.Conceptually, an assumption may be:
Strongly Supported
SupportedConditionally Supported
Weakly Supported
Unsupported but Necessary
or:Basis Undetermined
The classification should remain tied to the simulation inquiry.Assumption Justification
Assumption Justification explains why the simulation adopts a particularassumption.
Justification should answer:
Why is this assumption necessary?
Why is this assumption considered reasonable for this simulation?
What supports it?
Where does it stop being reasonable?
Assumption Materiality
A Simulation Assumption is material where changing, violating, or removing theassumption could materially affect: simulation behavior, scenario progression,
simulation outputs, interpretation, comparison, reality correlation,
downstream evidence, or reliance.
Material assumptions require stronger governance than assumptions with
negligible effect.
Materiality Is Purpose-Relative
The same assumption may be material in one simulation and immaterial inanother.
Example:
Stable network latency
may be immaterial for:high-level strategic simulation
but critical for:
real-time autonomous coordination simulation.
Critical Simulation Assumption
A Critical Simulation Assumption is an assumption whose failure couldmaterially alter or invalidate a major simulation conclusion.
Critical assumptions should remain highly visible.
They may require: stronger basis, stronger uncertainty treatment, explicit
scenario testing, sensitivity analysis, tighter monitoring, or narrower
interpretation.
Assumption Hierarchy
Assumptions may exist at different levels:Foundational Assumptions
support the overall simulation framework.Structural Assumptions
support model architecture or relationships.Environmental Assumptions
define simulated surrounding conditions.Behavioral Assumptions
define actor or system behavior.Parameter Assumptions
support selected parameter values or ranges.Scenario Assumptions
support specific simulated conditions.Interpretive Assumptions
affect how outputs are understood.SAS allows such classification without requiring one universal taxonomy.
Physical Assumption
A Physical Assumption concerns a physical relationship, condition, orconstraint.
Examples include: constant gravity, material stability, friction behavior,
heat transfer behavior, or known physical boundary conditions.
Behavioral Assumption
A Behavioral Assumption concerns expected behavior of: humans, AI systems,autonomous agents, organizations, biological systems, or other actors.
Behavioral assumptions may be especially sensitive where behavior is adaptive,
stochastic, strategic, or context-dependent.
Environmental Assumption
An Environmental Assumption concerns external conditions within the simulationenvironment.
Examples may include: weather range, infrastructure availability, traffic
behavior, communication availability, resource availability, or environmental
stability.
Dependency Assumption
A Dependency Assumption concerns the availability, behavior, reliability, orcharacteristics of something upon which the Simulation Object or simulation
environment depends.
Examples include: network availability, external database access, navigation
service availability, energy supply, human supervision, external AI services,
or supporting infrastructure.
Independence Assumption
Simulations frequently assume that variables, actors, events, or failures areindependent.
This may dramatically simplify simulation.
Where independence is false, resulting outputs may be materially distorted.
Therefore:
Assumed Independence must remain explicit where dependence could materially
change simulation behavior.
Stationarity Assumption
A Stationarity Assumption treats a relevant process or distribution assufficiently stable over time.
This may concern: human behavior, failure rates, demand, environmental
conditions, financial relationships, system performance, or operating
conditions.
Dynamic systems may invalidate stationarity assumptions rapidly.
Distribution Assumption
Stochastic simulations often rely upon assumed probability distributions.The chosen distribution should remain traceable to: evidence, domain
knowledge, prior observations, theoretical basis, or explicit approximation.
Boundary Assumption
A Boundary Assumption concerns conditions at or beyond the simulationboundary.
For example:
External network behaves according to defined latency profile.
The network may remain outside the Simulation Object while its behavior is
represented through an assumption.
Failure Assumption
A simulation may require assumptions regarding: failure frequency, failureindependence, propagation, degradation, recovery, or failure severity.
Where safety or resilience is material, such assumptions should receive
explicit governance.
Human Behavior Assumption
Human behavior may require assumptions concerning: reaction time,decision-making, compliance, intervention, error, variability, coordination,
or supervision.
SAS governs the assumption role.
CLIA® may govern the underlying cognition where applicable.
AI & Autonomous Behavior Assumption
Simulation of AI or autonomous systems may depend upon assumptions about:behavior stability, tool availability, permissions, perception, adaptation,
coordination, escalation, or environmental response.
AIG® and ASGA™ govern the underlying AI or autonomous operational spaces.
SAS governs specifically assumptions used inside the simulation.
Assumption Dependency
Assumptions may depend upon: other assumptions, evidence, model structure,parameters, environmental conditions, external systems, scenario conditions,
or operational constraints.
The relationship should remain visible where the validity or failure of one
assumption can affect another.
Assumption Chain
Simulation assumptions may form chains:Assumption A → Assumption B → Parameter Choice → Scenario Behavior →
Simulation Output
A weakness upstream may therefore propagate into downstream results.
SAS requires material assumption chains to remain traceable.
Assumption Interaction
Two individually reasonable assumptions may interact to produce anunreasonable combined simulation condition.
For example:
Assumption A: Human operator responds
within expected range
and:Assumption B: Network latency remains
within expected range
may individually be reasonable.Their simultaneous worst-case conditions may create materially different
system behavior.
SAS therefore allows assumption interaction to be governed collectively.
Assumption Accumulation
A simulation may contain hundreds or thousands of assumptions.Individually small assumptions may accumulate into a material combined effect.
SAS establishes:
Assumption materiality must be considered both individually and collectively
where cumulative effects may alter simulation meaning.
Assumption Uncertainty
An assumption inherently contains some degree of uncertainty unless it iseffectively an established condition.
SAS requires material uncertainty to remain visible.
Uncertainty may concern: whether the assumption is true, how broadly it
applies, how long it remains true, how stable it is, how variable the assumed
condition may be, or how sensitive the simulation is to assumption failure.
Assumption Uncertainty ≠ General
Simulation Uncertainty
SAS governs uncertainty specifically attached to Simulation Assumptions.It does not own every uncertainty in the simulation lifecycle.
Other uncertainty may arise from: data, model structure, execution,
measurement, representation, scenarios, or operational reality.
Assumption Range
Where a single assumed value is unjustified, an assumption may require arange.
For example:
Reaction Time = 0.8–1.5 seconds
may be more methodologically appropriate than:Reaction Time = 1.0 second
where real variability is material.Probabilistic Assumption
An assumption may be expressed probabilistically.This may be appropriate where uncertainty or variability can be represented
as: distribution, confidence interval, probability, likelihood class, or
stochastic rule.
Conditional Assumption
A Conditional Assumption applies only while a defined condition remains true.For example:
Navigation service assumed available while satellite visibility remains above
threshold X.
When the condition changes, the assumption may no longer be applicable.
Scenario-Specific Assumption
Some assumptions belong only to particular scenarios.A scenario-specific assumption must not automatically become a global
simulation assumption.
Assumption Sensitivity
An Assumption Sensitivity Assessment asks:How much does simulation behavior or output change when this assumption
changes within a plausible range?
Highly sensitive assumptions may require: stronger basis, wider scenario
exploration, explicit uncertainty propagation, or narrower output
interpretation.
Assumption Stress
A simulation may intentionally test what happens when an assumption isweakened, violated, or removed.
This helps distinguish:
Assumption-dependent result
from:robust simulation result.
Assumption Failure
An Assumption Failure occurs where an assumption becomes materiallyinconsistent with the represented or observed condition.
This may occur: during simulation, after new data appears, when reality
changes, when a model changes, when an environment changes, or when new
evidence demonstrates the assumption was incorrect.
Assumption Failure Does Not Automatically
Invalidate Entire Simulation
The consequence depends upon: materiality, affected scope, dependency chain,scenario, outputs, and whether the assumption can be replaced or bounded.
SAS therefore requires consequence assessment rather than automatic total
invalidation.
Assumption Consequence
A material assumption should identify what could happen if it is wrong ormaterially violated.
Possible consequences include:
No Material Effect
Local Simulation Effect
Scenario Limitation
Output Qualification
Model Reconfiguration Required
Additional Simulation Required
Reality Representation Reassessment
Required
Operational Interpretation Restricted
or:Consequence Undetermined Assumption
Limitation
An Assumption Limitation identifies the boundary beyond which the assumptionshould not support simulation interpretation.
For example:
Assumption valid only for temperatures
between X and Y
or:Assumption applies only to normal operating conditions.
Assumption Applicability
Each material assumption should remain connected to where it applies.Applicability may be bounded by: Simulation Object version, configuration,
environment, scenario, operating mode, population, temporal period, spatial
region, or other simulation context.
Assumption Status
A Simulation Assumption may hold a status such as:Established
Conditionally Established
Weakly Supported
Materially Uncertain
ConflictedFailed
Superseded
or:
Undetermined
Status does not establish universal truth.It establishes the current governance condition of the assumption within the
simulation.
Assumption Conflict
An Assumption Conflict exists where two assumptions or assumption basesmaterially contradict one another.
Example:
Assumption A: Communication delay is
negligible
and:Assumption B: Control behavior depends
upon material network latency
cannot both remain globally true without additional contextual separation.Material conflicts should be resolved or preserved explicitly.
Assumption Consistency
Assumptions across interacting simulation components should remain mutuallycoherent.
One component should not operate under:
constant environment
while another depends upon:
rapidly changing environment
without explicit governance explaining the difference.
Assumption Completeness
Assumption Completeness asks whether material assumptions supporting thesimulation have been sufficiently identified.
It does not require documenting trivial mathematical conventions with no
material simulation consequence.
It requires that material premises do not remain hidden.
Assumption Register
A governed simulation should maintain a persistent Simulation AssumptionRegister where appropriate.
The register may include: Assumption Identifier, assumption statement,
assumption type, affected object or process, basis, justification,
dependencies, uncertainty, materiality, sensitivity, applicability,
limitations, consequences, status, change history, and downstream references.
No Hidden Assumption Rule
SIMULOS® establishes:A material simulation conclusion must not depend upon a material assumption
that is absent from the governed simulation record.
No Assumption-to-Fact Conversion Rule
Repeated use of an assumption does not transform it into an established fact.No Convenience Justification Rule
An assumption must not be considered methodologically justified merelybecause: data are unavailable, modeling is difficult, computation is
expensive, the software uses that default, or the assumption produces
convenient results.
These may explain why the assumption exists.
They do not establish its methodological strength.
No Assumption Laundering Rule
An assumption introduced upstream must not disappear downstream and later berepresented as observed or validated reality.
Conceptually:
Assumption → Model → Output
must not silently become:Output → Evidence of the Assumption
without an independent basis.No Circular Assumption Confirmation Rule
A simulation should not be used as sole proof that one of its own foundationalassumptions is correct where the output structurally depends upon that
assumption.
No Assumption Stacking Concealment Rule
Several weak assumptions must not be treated as one strong simulation basismerely because their combined role is hidden.
No Assumption Scope Expansion Rule
An assumption valid within one context must not silently become applicableoutside that context.
No Retrospective Assumption Redefinition
Rule
Assumptions should not be materially redefined after outputs are known merelyto make the simulation appear successful.
Conservative Assumption
A simulation may intentionally adopt conservative assumptions.This can be appropriate in high-consequence settings.
However:
Conservative ≠ Automatically Valid
The conservative direction, basis, and consequence should remain explicit.Optimistic Assumption
Optimistic assumptions may also be legitimate in exploratory simulations.Their role should remain visible so that optimistic assumptions are not later
treated as neutral operational conditions.
Worst-Case Assumption
A worst-case assumption may support: stress testing, safety analysis,contingency planning, or resilience analysis.
The assumed condition should be distinguishable from expected operational
reality.
Representative Assumption
A simulation may use a representative value or behavior.The chosen representation should identify:
representative of what population, condition, environment, or period?
Without such context, “representative” can become meaningless.
Assumption Change
Simulation Assumptions may change when: new evidence emerges, OperationalReality changes, the Simulation Object changes, Reality Representation
changes, new scenarios are added, model structure changes, parameterization
changes, or previous assumptions fail.
Material changes should remain explicitly traceable.
Assumption Supersession
A new assumption may supersede a previous assumption.The previous assumption should remain historically traceable where it affected
earlier simulation activity.
Assumption Change Propagation
A material Assumption Change may affect: Simulation Model & Environment,parameters, Inputs & Data, Scenario Design, Execution, outputs, Reality
Correlation, Simulation Evidence, and downstream reliance.
SAS therefore treats assumptions as active lifecycle dependencies rather than
static documentation.
Assumption Reassessment Trigger
A material change in: evidence, reality, object version, configuration,environment, model, dependency, population, scenario, or intended use
may generate an Assumption Reassessment Trigger.
Assumption Versioning
Where a material assumption changes, the relevant assumption state shouldremain versioned or historically distinguishable.
Simulation runs based upon materially different assumptions should not
automatically be treated as directly equivalent.
Assumption-to-Execution Binding
Simulation execution should remain traceable to the set of materialassumptions active during that run.
Conceptually:
Simulation Assumption Set → Simulation Model & Environment → Simulation
Execution → Simulation Output
This allows later reconstruction of why outputs differed between simulation
runs.
Assumption-to-Output Binding
Where a material output depends strongly upon one or more assumptions, thatdependency should remain traceable.
This is especially important for: high-consequence conclusions,
sensitivity-sensitive outputs, extrapolated results, uncertain environments,
or simulations used as validation evidence.
Assumption and Reality Correlation
Later Reality Correlation may demonstrate that an assumption correspondspoorly to observed reality.
This does not mean SAS performs correlation itself.
It means the assumption lifecycle must remain capable of receiving new
information from downstream reality comparison.
Assumption and Validation
SAS does not determine whether an assumption is universally valid.VALIDOS® may validate: the assumption itself, its evidence basis, the
simulation, the resulting claim, or another relevant Validation Object.
The boundary is:
SAS governs the assumption as part of simulation.
VALIDOS® governs formal validation where required.
Assumption and Operational Reality
ORA™ may establish actual operational conditions relevant to an assumption.SAS does not replace ORA™.
It governs how simulation treats incomplete, expected, bounded, or presumed
conditions relative to that reality.
Assumption and Integrity
INTEGROS® may govern integrity of: assumption records, source records,configuration, traceability, or related lifecycle artifacts.
SAS governs specifically assumption identification, basis, dependency,
uncertainty, limitation, and simulation consequence.
Assumption and Auditability
ADIT® may preserve evidence showing: when assumptions were introduced, howthey changed, which simulation executions used them, and what outputs depended
upon them.
Assumption and Risk
RIS™ may inform which assumptions require increased attention where assumptionfailure creates high consequence.
SAS does not become a general risk architecture.
Assumption Basis Record
A governed Simulation Assumption Basis should preserve enough information toreconstruct: which assumptions existed, why they existed, what supported them,
what depended upon them, how uncertain they were, where they applied, what
limitations existed, and what consequences could result from failure.
Governance Boundary
SAS begins when:a governed Reality Representation Basis exists and the simulation requires
premises, approximations, expected conditions, or unresolved relationships to
proceed into model and environment construction.
SAS ends when:
material Simulation Assumptions have been sufficiently identified, supported
or explicitly qualified, linked to dependencies, bounded by uncertainty and
limitations, connected to their consequences, and preserved as a governed
Simulation Assumption Basis suitable for Simulation Model & Environment
governance.
Governance Scope
SAS governs assumptions specifically within the simulation lifecycle.It does not govern: universal truth determination, formal assumption
validation, general evidence validity, actual Operational Reality, model
construction itself, simulation environment configuration, parameter
implementation, input-data fitness, scenario execution, output validation,
general integrity, risk governance, or operational reliance authorization.
These responsibilities remain within the appropriate SIMULOS® Parent Standards
or complementary OOF® architectures.
Minimum Governance Requirements
A conforming application of SAS should establish:1. identifiable material Simulation Assumptions, 2. explicit conversion of
materially relevant implicit assumptions where feasible, 3. the basis and
justification for material assumptions, 4. assumption classification and
materiality, 5. identification of critical assumptions, 6. material assumption
dependencies, 7. assumption chains and interactions where relevant, 8.
uncertainty associated with material assumptions, 9. applicability and
conditionality, 10. sensitivity where assumption variation could materially
affect outputs, 11. explicit assumption limitations, 12. consequences of
assumption failure where material, 13. assumption conflict handling, 14.
traceability of material Assumption Changes, 15. and a persistent Simulation
Assumption Basis.
Relationship to Other OOF® Architectures
Simulation Assumption Standard interoperates with: GOA™ ORA™ VALIDOS®INTEGROS® ADIT® AGA™ AIG® CLIA® MGIA™ ASGA™ RIS™
while preserving strict architectural boundaries.
ORA™ may establish the actual Operational Reality against which simulation
assumptions are eventually compared.
VALIDOS® may formally validate assumptions, their evidence basis, simulation
outputs, or the simulation itself where validation is required.
INTEGROS® may govern integrity of assumption records and associated simulation
artifacts.
ADIT® may preserve the historical evidence and traceability of assumption
creation and change.
AGA™ may govern accountability for material assumption decisions.
RIS™ may influence the governance intensity required where Assumption Failure
creates substantial consequence.
AIG®, CLIA®, MGIA™, and ASGA™ may define domain-specific characteristics
relevant to assumptions about AI behavior, cognition, memory, and autonomous
operation.
SAS consumes those characteristics where necessary without replacing their
governance spaces.
Architectural Position
Simulation Assumption Standard (SAS) is the fourth Parent Standard of SIMULOS®— Simulation Governance Architecture.
The architecture progresses:
Simulation Object
↓Simulation Purpose & Scope
↓Reality Representation
↓Simulation Assumptions
SOS establishes:What exactly is being simulated?
SPSS establishes:
Why is it being simulated and what must the inquiry cover?
RRS establishes:
Which aspects of reality must be represented and how?
SAS establishes:
Which premises must be accepted so that this representation can become an
operational simulation, and what uncertainty, dependency, and limitation do
those premises introduce?
Once the governed Simulation Assumption Basis exists, the next architectural
question becomes:
How must the simulation model and simulation environment be constructed,
configured, bounded, parameterized, and version-controlled so that the
governed object, representation, and assumptions become an executable
simulation system?
This transition leads directly into:
Simulation Model & Environment Standard (SMES).