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Motivation GMP
• Client requirement
• Certification requirement (Delft3D, ISO)
• Efficiency and cooperation
• Knowledge management
• Training of new employees
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Content
• Introduction
• Quality and quality improvement
• Good Modelling Practice (7 steps; model journal)
• Modelling Guidelines
• Version Control
• Discussion
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Introduction
• Models are standard tools
• Might be routinely applied but subjective
• Depends on team and skills
• Often referred to as “the art of modelling”
• But unscientific and ambiguous aspects
• Risks:
• Many choices
• Complex
• Incomplete knowledge
• Result: many uncertainties
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Quality
• Models are used habitually
• Easiness to use enlarges risk of injudicious
use, e.g.
• Careless handling input data
• Insufficient calibration and validation
• Use a model outside its scope
• No predefined requirements
• Result
• Unrepeatable
• Trustworthiness unknown
• Not matching predefined prerequisites
Quality control
Quality control:
“Something
adheres to
some criteria”
Without a properly defined
something there is no basis
whatsoever for quality control.
• date x • batch no. x • ingredients x • calories x • ℮ gram x
• date √ • batch no. √ • ingredients √ • calories √ • ℮ gram √
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Quality control flavours
• Documents (Imandra, VF)
• Project management (APM)
• Health & safety (risk form)
• Tools (SVN subversion)
• Software (idem)
• Models (…?)
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Need?
• Is there a need to check and trace model
quality?
• If there is:
To which extent check and trace?
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How to check and trace?
Check:
• Based on set-up?
• Based on results?
• Based on report?
• Check against what?
Trace:
• Personal communication?
• Verification form/Model Journal?
• Version Control?
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Quality management
• Quality management common in software
engineering
• However, modelling quality often restricted
to verification and validation
• Five maturity stages (Scholten et al., 2007):
• Ad hoc
• Repeatable
• Defined
• Managed
• Optimized
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Ontology of modelling • “An explicit specification of a conceptualization”
Gruber (1993, 1995)
• Defines modelling
• Represents shared knowledge which can be
reused
• How:
• Dividing in activities to build/test
intermediate products.
• Based on general agreement and
negotiation (Scholten, 2007)
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1. Start model journal
2. Describe problem Define objective Specify requirements Make plan
3. Define/build model Make conceptual model Choose software Choose discretization Implement model Verify model
4. Test/check model Check mass balances Test sensitivity
Calibrate Validate Determine uncertainty
5. Run model Make application plan Run model Check results
6. Describe results Discuss results Describe conclusions Check objective Analyse consequences for problem
7. Report and archive Check model journal and templates
Good Modelling Practice flow chart defines modelling process Use Modelling Guidelines as reference
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Modelling Guidelines • Introduction
• Data
• Bathymetry, Topography, Coastlines, Tidal
constituents, Discharges, Water levels, Wind,
Waves, Tsunamis, Sediment, Temperature and
salinity
• Model set-up
• Define model area, resolution and grid layout,
check grid quality, convert bathy samples,
interpolate bathy, schematize sediment, boundary
conditions
• Model calibration and validation
• (Technical) report
• See above
• + criteria for figures and tables
• + MATLAB tips and tricks
Quality control
Quality control:
“Something
adheres to
some criteria”
Without a properly defined
something there is no basis
whatsoever for quality control.
GMP flow chart (model journal)
and Modelling Guidelines
should be accompanied by
Version Control
• date x • batch no. x • ingredients x • calories x • ℮ gram x
• date √ • batch no. √ • ingredients √ • calories √ • ℮ gram √
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Good Modelling Practice
Why:
• Client requirement
• Certification requirement (Delft3D, ISO)
• Efficiency and cooperation
• Knowledge management
• Training of new employees
How:
• Make Model Journal using GMP flow chart
• Use Modelling Guidelines as reference
• Use Version Control for models and scripts
Delft3D Flexible Mesh facilitates parts of the Model Journal and Version Control
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References
• Roelvink & Reniers (2012). A guide to modelling coastal morphology.
World Scientific.
• Scholten et al. (2007). A methodology to support multidisciplinary
model-based water management, Environmental Modelling &
Software 22 (2007) 743-759
• Refsgaard et al (2005). Quality assurance in model based water
management – review of existing practice and outline of new
approaches. Environmental Modelling & Software 20 (2005) 1201–
1215
• Scholten et al. (2000). Good Modelling Practice in water
management. HydroInformatics 2000, 23-27 July 2000, Cedar
Rapids, IA, USA
• Van Waveren et al. (1999). Good Modelling Practice Handbook.
STOWA report 99-05.