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Visual Comparison of Enterprise Models Using Syntactic Model Information. Jean-Paul Van Belle jvbelle@commerce.uct.ac.za. Why research "visualization of models"?. You get interesting results!. Slides,. waves. and roller-coasters. Research Objective.
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Visual Comparison of Enterprise Models Using Syntactic Model Information Jean-Paul Van Belle jvbelle@commerce.uct.ac.za
Why research "visualization of models"? You get interesting results! Visual Comparison of Enterprise Models ACIS'03
Slides, waves androller-coasters Visual Comparison of Enterprise Models ACIS'03
Research Objective • Find an immediately intuitivecharacterisation and visualization of the (syntactic & semantic) comparison of modelswithin a particular application domainNotes: • Descriptive – not normative (yet)! • Existing metrics not satisfactory • Real-world test bed Visual Comparison of Enterprise Models ACIS'03
Overview • Introduction: The research context • Overview of the Enterprise Models • Problems with SE metrics for models • Graph analysis approach • Fan-out Frequency Distributionplot & signature • Visual interpretation of semantic distance Visual Comparison of Enterprise Models ACIS'03
See also: Chris Taylor @ QUT Framework for Analysis & Evaluation of Models Visual Comparison of Enterprise Models ACIS'03
The Model Database • Purpose: to serve as a validating test bank for the analysis framework. • Model Selection Criteria: • Domain = “The Generic Enterprise” • Sufficiently large size • ~200 entities; ~300 relationships • Publicly available • From very different reference disciplines Visual Comparison of Enterprise Models ACIS'03
The Models: Systems Engineering • Reference Frameworks • Purdue • Nippon • ARRI • OO • BOMA • Fowler (patterns!) • San Francisco • ERD Libraries • Silverston • Hay Visual Comparison of Enterprise Models ACIS'03
The Models: Practitioners • ERPs • BAAN • SAP R/3 • Real organisations • AKMA • NHS • Data warehousing • Inmon Visual Comparison of Enterprise Models ACIS'03
The Models: Various • Ontologies • TOVE • CYC (subset) • AIAI • Miscellaneous • Miller (systems theory) • Ottawa (linguistic) • Random • Finance • Belgian Accounting • USB Growth Model Visual Comparison of Enterprise Models ACIS'03
Non-visual approaches:Model metrics • Structural metrics relate to the number of nodes (entities) and arcs (relationships between the entities). • Inheritance metrics investigate the characteristics of the inheritance trees. • Grouper metrics take into account the modularity of the model by means of the grouper constructs Visual Comparison of Enterprise Models ACIS'03
Structural metrics • McGabe’s cyclomatic complexityCC = # relationships - # entities + 1 • Relative connectivity= # relationships / # entities • DeMarco’s DataBang= REi (# relationships for ith entity) x wi (ith entity’s weighting factor). Visual Comparison of Enterprise Models ACIS'03
Structural Metrics: Deficiencies • # Entities/Relationship: a rough size indicator but no proxy for complexity • Cyclomatic Complexity is meaningless (not normalized for model size!) • Relative connectivity & fanout are skewed by outliers • Data bang metrics are of little or no interpretative value Visual Comparison of Enterprise Models ACIS'03
Visualizing Model Structure • Graph Analysis Packages • Plot of Fan-out Distributions • Descriptive Statistics • Proposed Fan-out Distribution Statistics Visual Comparison of Enterprise Models ACIS'03
Graph Analysis Packages • The model as a directed graph or network • Many tools available • E.g. PAJEK: Package for Large network Analysis (Vlado Group, Univ Ljubljani, Slovenia) • Problem: visualization “bunch of lines” • The key element = fan-outs! Visual Comparison of Enterprise Models ACIS'03
BAAN Hay InmonSilverst. Visual Comparison of Enterprise Models ACIS'03
Clustering (Fruchterman-Reingold) Visual Comparison of Enterprise Models ACIS'03
"bunch of lines"Intuitive? Interpretation? • Essential element of complexity / syntactic structure = network • Essential element of network => connectivity or fan-out • Average fan-out => too simplistic • => Look at entire distribution of (entity) fan-outs Visual Comparison of Enterprise Models ACIS'03
Plotting the Fan-out Frequency Distribution Visual Comparison of Enterprise Models ACIS'03
Descriptive Statistical Measures • Central location (“average”) • Arithmetic; median; mode; harmonic • Dispersion (“spread”) • Standard deviation; range • Skewness (“ symmetry”) • 1st & 2nd Pearson coeff.; 3rd moment • Peakness / curtosis (“pointedness”) • Coeff. of curtosis; adjusted 4th moment Visual Comparison of Enterprise Models ACIS'03
Proposed Measures • Curve shape family • Waves slides (& rollercoasters) • Bumpiness / smoothness • Number of inflexion points • Exceeding a minimum threshold (2.5%) • Degree of curvature (“bentness”) • Fit the cumulative freq distribution with y=tanh(x/h) function (1 param, good fit) Visual Comparison of Enterprise Models ACIS'03
Slides, waves & roller-coasters Visual Comparison of Enterprise Models ACIS'03
Plotting the Fan-out Frequency Distribution Visual Comparison of Enterprise Models ACIS'03
Proposed Measures • Curve shape family • Waves slides (& rollercoasters) • Bumpiness / smoothness • Number of inflexion points • Exceeding a minimum threshold (2.5%) • Degree of curvature (“bentness”) • Fit the cumulative freq distribution with y=tanh(x/h) function (1 param, good fit) Visual Comparison of Enterprise Models ACIS'03
Syntactic Semantic analysis • Syntactic=> appearance or shape of model network ("nodes & links") • Semantic=> meaning of network => partly captured in e.g. entity names=> "semantic overlap" (or distance) between models Visual Comparison of Enterprise Models ACIS'03
Semantic Overlap Visual Comparison of Enterprise Models ACIS'03
Semantic DistanceDendogram Visual Comparison of Enterprise Models ACIS'03
Conclusions & Future Research • Traditional measures not very useful • Suggested measures seem to work very well for visualization • Normative interpretation? • Other domains? Visual Comparison of Enterprise Models ACIS'03