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We build models to ask and answer questions...

...questions about system, system of systems (SoS), and process behaviors. 

Students, researchers and practitioners are using MP to answer questions such as:

  • What is the intended sequence of events?
    • How should the system handle disruptions?  
  • How many scenarios contain unexpected behaviors?  
    • What formal constraints / requirements will prevent unwanted unexpected behaviors?
  • Which events must be managed as an enterprise risk?
    • Which are the critical decision points?
    • Which have the highest consequence?
  • What is the expected duration of a behavior sequence (scenario)?
    • What is the downstream consequence of an upstream disruption?
  • What behavior patterns are present in the model?
    • Is a presented pattern also applicable in other domains?
  • —In which traces are certain wanted or unwanted behaviors or patterns present? 

Other questions that can be answered with MP :

  • Is a known unwanted behavior absent from all traces / the design?
  • What could the unwanted behaviors have cost later, had they not been exposed early?
  • How many valid event traces remain after removal of unwanted event traces?
  • —How many failure modes are included among the valid event traces?
  • —What is the probability or likelihood of an event or outcome?
    • Given the presence or absence of other events?
    • —What is the likelihood of success/failure?
  • —Which behaviors have the most severe impact / consequence and how likely are they to occur?
    • How should event traces be prioritized for the risk management?
  • —What is the expected/minimum/maximum value of a resource (time, money, fuel, power, water, food, projectiles, waste, etc.) a process / behavior sequence can produce or consume at a given scope?

    • What is the probability or likelihood a process will produce or consume more or less of a resource in a given amount of time?
  • —How is overall behavior impacted if not enough resources are available for a given event to start or finish?

Application Domain Examples

See below for example MP models in different application domains.

Mission Engineering

This solution-neutral operational process model of a Search and Rescue (SAR) mission shows the required interactions among five participants.

Run it here:  https://firebird.nps.edu/?example=Example08_Operational_Process

Business Process / Workflow Modeling

This model of the spiral software process illustrates the use of MP to model high level processes employed by individual roles within an organization.

Run it here:  https://firebird.nps.edu/?example=Example16_software_spiral_process

Policy

A model of an overdose situation to inform policy on rescue medication administration turns up an unintended scenario in which the victim receives the rescue medication twice from lack of coordination.

Run it here:  https://firebird.nps.edu/?example=Example53_First_Responder

Autonomous Systems

A UAV is decomposed into subfunctions that interact with the operator and the environment. Automated annotations describe important aspects of this scenario.

Run it here:  https://firebird.nps.edu/?example=Example58_UAV_OnStation

Aero

A commercial flight is modeled, showing interactions among passenger, pilot and controller (top row) across seven phases (left column).

Run it here:  https://firebird.nps.edu/?example=Example50_Flight

Space

A scenario from a model of a spacecraft communications system as it approaches to dock with the International Space Station (ISS). The absence of this particular scenario from the model was noticed and subsequently corrected by the student author.


Run it here:  https://firebird.nps.edu/?example=Example54_Unmanned_Spacecraft_Comms

Software Architecture

A scenario from an MP model of an unconstrained stack (allowed to try to pop an empty stack) illustrates how to pinpoint events that violate a certain property, and how to annotate these particular events in the trace with additional messages.

Run it here:  https://firebird.nps.edu/?example=Example07_Unconstrained_Stack

Networks & Communications

An example scenario from a model of network ring, where each node interacts with its left and right neighbors only.

Run it here:  https://firebird.nps.edu/?example=Example12_network_topology_ring

General Systems and Emergence Research

An MP model of the Cycles isomorphic systems process (ISP) containing two of at least five cycles patterns shown to arise from a small model of 6 lines of code.

Run it here: https://firebird.nps.edu/?example=Example59_Cycle_Pattern

Automotive

A scenario from a model of an autonomous automobile's interactions with its user.


Run it here:  https://firebird.nps.edu/?example=Example51_Autonomous_Car

Manufacturing

A scenario from a model of a manufacturing process.


Run it here:  https://firebird.nps.edu/?example=Example48_Manufacturing_Process

Logistics

A scenario from a model of a logistics process (two producers, transportation, supply office, and two consumers).

Run it here: https://firebird.nps.edu/?example=Example19_Consumers_Suppliers

Healthcare

A scenario from a model of a decision making process in the context of a medical procedure (a physician in the leader role, and nurses in the subordinate role).

Run it here:  https://firebird.nps.edu/?example=Example60_Surgery

Power & Energy

An example scenario from a model of a spent nuclear fuel cooling pool shows the interactions between the cooling pool and external systems including operator, heat exchanger, and water makeup system.


Run it here: https://firebird.nps.edu/?example=Example61_Spent_Fuel_Cooling_and_Cleanup

Sports & Entertainment

An example model from a car race model with two cars and a judge.

Run it here: https://firebird.nps.edu/?example=Example05_Car_Race



Lifecycle Phase Application Examples

Concept of Operations

Use MP during concept development to create a model of the problem.  Show the MP event traces to stakeholders for feedback on whether or not the model accurately and fully captures the problem to be solved.  Fix misinterpretations about the problem. 

Requirements & Architecture

Use MP to describe the architecture-level behavior that solves the problem of interest.  Formulate and test the logic, completeness and consistency of requirements for the system under design. Fix misinterpretations and errors pertaining to the architecture of behavior of the high level elements.

Detailed Design

Use MP to describe the detailed behaviors as allocated to software, hardware, people, facilities, or some combination thereof.    Fix errors in component behaviors.

Integration, Test, and Verification

Use MP to systematically create an exhaustive set of test cases up to the user-defined scope limit, from which a subset may be selected and prioritized for live testing.  Use live test results to validate synthetic test results that were obtained through simulation only.  Use simulation results to verify that scenarios that could not be live-tested also meet requirements.

System Verification & Validation

MP helps us make more complete predictions about possible alternative system behaviors, learn about critical issues are concerning interactions among parts of the system and between the system and its environment, and exclude undesired behaviors from the design before their manifestation in the actual system.  With MP, verification & validation of the system model is concurrent with model development throughout every phase of the lifecycle.  During this phase the actual system behavior is checked against the MP-modeled system behavior.

Operations & Maintenance

An MP model of a fielded system may be used as a "digital twin" to verify and validate proposed changes to the configuration before actually making those changes in the real system.


Material contained herein is made available for the purpose of peer review and discussion and does not necessarily reflect the views of the Department of the Navy or the Department of Defense.

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