integration of simulation results into information systems

Gio Wiederhold SimQL 1

Integration of Simulation Results into Information Systems

Gio Wiederhold

April 2002


Information Integration

Information Integration provides new Information for improved Decision Making when it

presents more data Risk: much may be irrelevant

captures new relationships Often requires expert inter-domain knowledge

includes current sensor data Data reflect the past only

includes predictions about future courses

******* A new, potentially major topic *******


Decision-making (DM)

Analyze Alternatives

• Current Capabilities

• Future Expectations

Process tasks:

• List resources

• Enumerate alternatives

• Prune alternative

• Compare alternatives

futurenow


Prediction Requires Tools

E-mail this book, Alfred Knopf, 1997


Future information systems

Combine data from the past, with current data, knowledge, and predictions into the future

o oo o

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Assessment of the values of alternative possible outcomes


DM support is disjoint

Distribution

Databases

Simulation

Planning Science

extensions to moveto networked supportare also disjoint

does not interoperate


Current state of DM Support

• Spreadsheets

• Planning of allocations

• Other simulations

various point assessments

past now futurepast now futuretimetime

Data integration

distributed, heterogeneous

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Databases

Intuition +

organized support disjointed support


Information Systems should alsoProject into the Futures

Support of decision-making requires dealing with the futures, as well the past

• Databases deal well with the past

• Sensors can provide current status

• Spreadsheets, simulations deal with the likely futures

Information systems should be able to combine all three

timetimepast now futurepast now future


A new Resource for Information

Application Layer

Mediation Layer

Foundation Layer

data and simulation resources

value-added services

decision-makers at workstations


Interfaces enable integration:SimQL to access Simulations

timetimepast now futurepast now future

Msgsystems,sensors

Databases, accessed via SQL or

XML, CORBA compliant wrappers

Simulations, accessed via SimQL and

compliant wrappers


Stanford experiment, supported by DARPA & NIST

Phase 1 Architectures

SpreadsheetsEngineering

wrapper wrapperwrapper

LogisticsApplication

ManufacturingApplication

Weather (short-, long-term)

wrapper

TestData

SimQL accessSimQL access

SimQL access

SQL access


5 DevelopAssessment Plan

7

2 Develop *Objectives

*: w/Measures

4 AssignTask / Activity

3 Phase & *SequenceObjectives

1Determine

StatusExecution Feedback

Higher Level Objectives, Intel, OB,ROE, Commanders Guidance & Intent, Etc.

Plan Assessment Feedback

Resource Constraints

Required Resources

Phased Sequenced Objectives

Assessment Plan

Prioritized Sequenced Tasks

Campaign Status

Access to Simulations

Req’mtsDetermine

Assess and/orRehearse Plan

SimQL

Place of SimQL in Objective-based Planning

from JFACC PIP

Simulationresults

Simulationparameters


Types of simulation services

1. Continously executing: weather prediction– SimQL result reports best match samples

2. Execution specific to query: what-if assessment– may require HPC power for adequate response

3. Past simulations collect results in a base: materials– performs inter- or extra-polations to match query parameters

4. Combinations, i.e., 2. + 3.: top layer simulation using stored partial lower level results: weapon performance in new setting

5. Human-in-the-loop (mediated by an agent program): SAFs

Note• A simulation service program can be written in any language• A simulation service must be compliant to the interface spec.


Enabling Interoperation

Databases• serve clients via SQL by

Sharing a Model (The Schema)

A query language over the model the SQL interface enables• independence of

application developmentDBMS technology developmentreuse of infrastructure

Today• most new systems use a

DBMS for data storageeven with less performance, inability to handle all problems,but enough of them well enough.

Simulations should • serve clients via SimQL by

Sharing a Model (research q.)A query language over the model

a SimQL interface enables• independence of

application developmentsimulation technology develop’treuse of infrastructure

Objective• build information systems

combining DBMS, Simulationseven with less performance, inability to handle all problems,but enough of them . . .


Internet requirements

• Ubiquitous access to simulations

of a wide variety of types

• Rapid response to parameter changes– often High-Performance computation is

needed– distributed simulations with synchronization

• Rapid Service Composition – High bandwidth among simulations– Acces to multiple services in parallel


Even the present needs SimQL

timetimepastpast now now futurefuture

last recorded observations

simple simulationsto extrapolate data

Is the delivery truck in X?

• Is the right stuff on the truck?

• Will the crew be at X?

• Will the forces be ready to accept delivery?

point-in-time for situational assessment

Not all data are current:


Use of Simulation Results

Simulation results can be composed for alternative Courses-of-actionsComposition should include computation

and recomputation of likelihoods Likelihoods change as now moves forwards

and eliminates earlier alternatives.

timetime0.40.4

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0.10.1

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0.10.1

0.50.5 0.30.3

0.20.2

prob


The branches can be labeled with probabilities, then assessed using the outcome with values

past now futurepast now future

Next period alternatives

0.4

0.6 and subsequent periods

0.2

0.1

0.5

0.30.2

0.1

0.1

0.13

0.3

0.2

0.07

0.4

0.3

0.1

10001000

20002000

50005000

10001000

00

-6000-6000

-3000-3000

ValuesValues

100100

600600

1100 5001100 500

200 200200 200

-420 0-420 0

-820 -400-820 -400

12001200

6666

134134

-1220-1220

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timetime

prob

value


Integrating data & planning support will make our data reusable and much more valuable

past now futurepast now future

Re-assess as timeRe-assess as timemarches forward !marches forward !

A Pruned Bush A Pruned Bush

Databases, . . .Spreadsheets,

other simulations,

Msgssensors

10001000

20002000

50005000

10001000

00

100 100

600600

1100 5001100 500

200 200200 200

00

12001200

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timetime

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New DecMk research questions

• How to move seamlessly from the past to the future?

• How can multiple futures be managed (indexed)?

• How can multiple futures be compared, selected?

• How should joint uncertainty be computed?

• How can the NOW point be moved automatically?


Current State of SimQL research

Spreadsheets Weather Engineering

wrapper wrapper wrapper

Test Application

GUIcollect language

requirements


SimQL research questions

• How little of the model needs to be exposed?

• How can defaults be set rationally?

• How should expected execution cost be reported?

• How should uncertainty be reported?

• Are there differences among application areas that require different language structures?

• Are there differences among application areas that require different language features?

• How will the language interface support effective partitioning and distribution?


Moving to a Service Paradigm

• Server is an independent contractor, defines service

• Client selects service, and specifies parameters

• Server’s success depends on value provided

• Some form of payment received for services

x,y

Databases are a current example.Simulations have the same potential.


Summary of SimQL

A new service for Decision Making:• follows database paradigm

– ( by about 25 years )

• coherence in prediction– displacement of ad-hoc practices

• seamless information integration – single paradigm for decision makers

• simulation industry infrastructure– investment has a potential market– should follows database industry model:

Interfaces promote new industries

integration of simulation results into information systems

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