Visualizing SISO Smackdown Scenario

with OPM and HLA

Israel Institute of Technology – Technion, 2012

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Technology:Object Process Methodology (OPM) Modeling for Development of HLA

Simulations

• Model Generated BOM/HLA Products Procedure• Model Based Simulation Scenario Development

Products:

Applicability: Sim of Lunar Exploration Architectures

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OPM-BOM Translation

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IntroductionThe BOM generation analysis focused on two variations of object

models: Object Process Methodology (OPM) and Base Object Model (BOM)

The aim is to develop and implement rules of mapping from OPM to BOM.

The staff: Mr. David Howes, former NASA engineer (USA). Prof. Dov Dori, supervisor of the project. Mr. Sergey N. Bolshchikov, graduate student of Information

Systems Mr. Noam Shmueli, graduate student of Information Systems Mrs. Michal Ezion, student of Information Systems Mrs. Hadar Bibi, student of Information Systems

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Short OPM descriptionThe OPM model consists of a set of:

Object Process Diagram (OPD set) and a corresponding

Object Process Language (OPL text).

The OPL sentence generated in response to the model.

The root diagram is the most abstract level called:

System Diagram (SD)

The OPDs in the OPD set are hierarchical by construction via recursively

zooming into process(es) of interest.

Each is a refinement of its ancestor.

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Example OPM SD0: Meal preparing

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SD1: Meal preparing in zoomed

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OPM componentsOPM Entities The bricks: Things and States Object: a thing that exist or might exist. Process: a thing that happens to an object and transforms it.OPM Links Structural Link: specifies a static, time-independent, long-lasting aspect of the

system. Connect two objects or two processes. Procedural Link – Enabling or Transforming Link: specifies a procedural, behavioral, time-dependent, or

dynamic aspect of the system. Connect an object and a process.

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OPM- Entities

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OPM- Structural Links

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OPM-Procedural Transforming Links

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OPM-Procedural Enabling Links

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OPM- Procedural Control Links

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Goal

We focus on four tables related to Conceptual Model Definition: 1. Pattern of Interplay provides a mechanism for identifying sequences of pattern

actions. 2. State Machine provides a mechanism for identifying the behavior states

expected to be exhibited by one or more conceptual entities. 3. Entity Type provides a mechanism for describing the types of conceptual

entities used to represent senders and receivers. 4. Event Type provides a mechanism for describing the types of conceptual

events.

To develop and implement a correct mappingmechanism between OPM and BOM for

High-Level Architecture utilizing.

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DescriptionThe work was performed in four Steps:Learn OPM: We took two courses on OPM: Specification and Analysis of Information

Systems and Methodologies in Information Systems Development. Learn BOM: We studied the BOM template specification, Prepared by SISO Base

Object Model Product Development Group. Develop the mapping rules: We analyzed the OPM diagram bottom up– from the leaves to the tree

root. We matched the OPM components and OPM rules to those in the BOM, by analyzing parallels between OPM entities and links and the four BOM’s tables.

Implementation Logic:We transformed OPM XML representation to data structure of graph in

Python code.We applied the rules on the graph representation and supply the BOM tables,

again in Python code.We transformed the BOM tables into BOM XML representation.

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Process name of leaf

Sub Process name of leaf

Agent/ instrumen

t link

Result link

A process is a thing that transforms an object.

An instrument link is a procedural link that needed for the process to happen, but it is not transformed by the occurrence of this process.

An agent link is a procedural link that connects a process with an human enabler of that process but is not (significantly) affected by it.

A result link is a transformation link that connects a process with an object that yield it.

OPM-BOM Translation Example

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Consumption/ Effect link

State associated with condition/ event

link

Invocation link

Object associated with condition /event Link

A consumption link is a transformation link that connects a process with an object and consume it. An effect link is a bidirectional arrow, between the affecting (state-changing) process and the affected object—the object whose state has changed as a result of the process occurrence.

An event link is a procedural link from a triggering object or object state to the triggered process. A condition link is akin to an "if…then" command: If a condition link originates from the state, the semantics is "do if.”A condition link is akin to an "if…then" command: If the object is at the state from which the condition link originates, then execution of the target process

An invocation link is a direct link between an invoking process and an invoked one, where the object created by the former process triggers and is immediately consumed by the latter.

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Mapping Table - Pattern of InterplayOPM BOM Comment

1Process Name of leaf

Pattern of Interplay Name

Diagram in the tree

2 Sub Process Name of leaf

Pattern Action Name

3Agent /Instrument Link Sender

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Consumption Link

Sender/ Receiver Need to check if the sender and the receiver are the same: If already exists sender, then the object that is connected with consumption link is the receiver. If already exists object with consumption link take it as sender.

5 Result Link Receiver6

Effect Link

Sender/ Receiver Need to check if the sender and the receiver are the same: if already exists sender, then the object that is connected with effect link is the receiver.If already exists object with result link take it as sender.

7 State associated with condition /event link

Event

8Object associated with condition /event Link

Condition

9Invocation Link

Receiver and Event

We create a new object called "Output of the top process' name". This object is the receiver of the top process and the event of the above process.

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Pattern of Interplay

Notes:We do not produce variants. Possible to do with process

inheritance.We do not produce exceptions since OPM defines time

exceptions that are not BOM exceptions.Exception:

If the sub process is connected to an attribute, then this is not a sender.

Solution: we navigate to the object that exhibits the attribute and make it a sender.

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Object NameObject State Process with Result

LinkObject State

An object is a thing that exists or might exist

A state is a possible situation or position at which an object can be or a value it can assume for some positive amount of time.

A result link is a transformation link that connects a process with an object that yield it.

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Mapping Table – State MachineOPM BOM

1 Object Name State Machine Name, Conceptual Entity

2 Object State State

3 Process with Result Link Exit Action

4 Object State Next State

Note:Exit Condition consists of Exit Action and Next State.Assume that changing of object state is done by only one process.In other words, changing from state 1 to state 2 is done by process A, changing from state 2 to state 3 is done by process B and so on.

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Object Object statesObject attributes (Exhibition /

Aggregation)

Exhibition-Characterization, which denotes the relation between an exhibitor—a thing exhibiting a one or more features (attributes and/or operations) and the things that characterize the exhibitor.

Aggregation-Participation, which denotes the relation between a whole and its parts.

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Mapping Table - Entity Type

OPM BOM

1 Object Entity Type Name

2 Object statesEntity Type Characteristics Name

3 Object attributes (Exhibition / Aggregation )

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Agent LinkInstrument Link

Result LinkProcess Name

of leafEffect Link Instrument

Event LinkConsumption

Event Link

An instrument event link is a combination of an instrument link and event link. Being an event link, it triggers a process. Being an instrument link, it leaves the triggering object unchanged.

A consumption event link is a combination of an event link and a consumption link. Being an event link, it triggers a process Being a consumption link, it indicates the (conditional) consumption of the triggering object

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Mapping Table - Event Type

OPM BOM

1 Agent LinkSource Characteristic

2 Instrument Link

3 Result Link Target Characteristic4 Process Name of leaf Event type name

5 Effect Link Content Characteristic

6 Instrument Event LinkTrigger Condition

7 Consumption Event Link

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BOM Generation Analysis Summary and Future WorkThe initial work of translating Object-Process

Methodology into Base Object Model for High-Level Architecture translates OPM Diagram into 4 main BOM tables – Pattern of Interplay, State Machine, Entity Type, and Event Type – with certain limitations.

The future work includes reducing translation limitations; translating OPM into more BOM tables; support of BOM federation.

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OPM Scenario Model

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Rationale for Model Based Sim Scenario Development A conceptual “architecture” for a sim is usually

power point based, leaving a concept details gap before more detailed studies commence

A model based sim concept definition builds a basis for following studies upon a conceptual model of the goals of the simulation with its objects and their behavior

The model is developed top - down with increasing levels of detail, providing a structured, orderly development

Two models are developed: Design model - no HLA details Implementation model - with real time and HLA

details28

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OPM Model Based Scenario Development FeaturesThe model provides a top-down description of the

scenario’s structure and behaviorThe model includes real-time representationsNecessary conditions for an activity are explicitThe model can also provide an HLA oriented

representation of the simulation as opposed to just a system only representation

Element processes in the OPM model corresponds to element software modules

OPM has one model diagram type with dual cognitive representation

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OPM System (Context) Diagram

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Lunar Mining and Transporting In-zoom

OPM symbology provided in the appendix

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An Example HLA Implementation in an OPM Model This is a model fragment for a cargo transfer from the Lunar Transfer

Vehicle to the Lunar Shuttle The raising of an interaction for the transfer is represented The TV Docked Interacting process changes the vehicle states and

triggers the interaction

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Model Equivalent Text

TV Docked Interaction triggers LS Cargo Transferring Action.Sim Transfer Vehicle is a Transfer Vehicle.Sim Transfer Vehicle can be undocked, Docked, hasCargo, or noCargo.Sim Transfer Vehicle exhibits TV Cargo Weight.            TV Cargo Weight can be xxxx or 0.Sim Transfer Vehicle triggers TV Docked Interacting when it enters Docked.Sim Lunar Shuttle is a Lunar Shuttle.Sim Lunar Shuttle can be undocked, docked, noCargo, or hasCargo.Sim Lunar Shuttle exhibits LS Cargo Weight.            LS Cargo Weight can be 0 or xxxxx.Sim Lunar Shuttle triggers TV Docked Interacting when it enters docked.TV Docked Interacting requires Docked Sim Transfer Vehicle and docked Sim Lunar Shuttle.TV Docked Interacting changes Sim Lunar Shuttle from noCargo to hasCargo, Sim Lunar Shuttle from noCargo to docked, Sim Lunar Shuttle from undocked to hasCargo, Sim Lunar Shuttle from undocked to docked, Sim Transfer Vehicle from hasCargo to noCargo, Sim Transfer Vehicle from hasCargo to Docked, Sim Transfer Vehicle from undocked to noCargo, and Sim Transfer Vehicle from undocked to Docked.TV Docked Interacting yields TV Docked Interaction.LS Cargo Transferring Action requires TV Docked Interaction.LS Cargo Transferring Action changes LS Cargo Weight from 0 to xxxxx and TV Cargo Weight from xxxx to 0.

This textual representation of the cargo transfer model provides cognitive based crosscheck on

developing the model

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Scenario Products Developed Detailed outline of a scenario for a Lunar

mining mission Used for developing consensus on mission

activities OPM scenario design model down to first

level of interplay among mission elements Developed to identify element modes,

commands, and states which would support element interactions

Protocol communication model for Lunar orbiting communications satellite Sub-model to develop agreement on a

communications protocol32