*Based on the work of Peter Coad, Stephen R. Palmer and others Advanced Domain Modeling Architecting for Agility with Color Models* David J. Anderson Program Manager, Microsoft

Objectives Peter Coad and Patterns –A brief history of how color modeling came about Archetypes and the Domain Neutral Components Modeling for Agility –Loose coupling and Law of Demeter Advances in Color Modeling since 1999 –The role of >s –Getting the blues –Whole-part relationships –Patterns of color communicate architecture smells –Enterprise components from color models

History

Object Models : Strategies, Patterns & Applications, 1st ed., Coad, Mayfield & North, Yourdon Press, Prentice Hall, 1995 RoleTransactionThing Catalog Description History

[*still referred to as “Transaction” in], Object Models: Strategies, Patterns & Applications, 2nd ed., Coad, Mayfield & North, Yourdon Press, Prentice Hall, 1997 Moment or Interval – a generalization of the idea of a transaction e.g. Warranty Period Period of Employment Loan Approval Request Funds Disbursement Employee > PeriodOfEmployment >* OrganizationUnit Name=KC Branch > OrganizationUnitDescription Description = Branch Office > History – Spring 1997

Color instantly communicates the pattern of class relationships to the viewer If the colors are not configured in the correct pattern then there are strong clues that the model could be improved! History – September 1997

Phil Bradley was Development Manager Persistence Layer, PowerLender Project, United Overseas Bank, Singapore Philip Bradley argues for Archetypes not stereotypes. “ a model from which all things of the same kind more or less follow” And that, all business flows should or ought to be basically the same. “Data Model Patterns - Conventions of Thought”, David Hay, Dorset House, 1996 “ a conventional, formulaic, over-simplified conception, opinion or image” rather than [The Universal Data Model] Dec 1998 – Archetypes

“Java Modeling in Color : Enterprise Components and Process”, Coad, Lefebvre and De Luca, PTR-PH 1999 History – January 1999

Architecture Board

Component Map

Archived Iteration

Elegant Enough to get the job done and no more Extensible Loosely coupled Robust and resilient to change Communicates clearly “ In anything at all, perfection is finally attained not when there is no longer anything to add, but when there is no longer anything to take away” Antoine de Saint Exupery Definition of an Agile Model

Behavior of Colors Instances of Archetypes share similar attributes Instances of Archetypes share similar methods assessPerformance() salesMadeInPeriod() averageSalesOverPeriod() assessAccuray() assessSpeed() isActive() isSuspended() totalValue() isComplete() isUrgent() _findByIdNumber() _findByName() isOfType() getValue() assessAcrossRoles() listRolesPlayedBy() totalUnitsAvailable() totalUnitsManufactured() assessRoleAllowed() Courtesy Stephen R. Palmer

Where do >s come from? OK! Better!

Naming Conventions for Roles Note: the actual aggregating > is used for naming rather than the > When no domain specific term for a > exists use the template –Person|Place|Thing In Moment-Interval –Or, GreenInPink e.g. ItemInSale

Roles and Inheritance Courtesy Stephen R. Palmer

Inherit from a Role superclass Courtesy Stephen R. Palmer

Manage roles with a description Courtesy Stephen R. Palmer

Courtesy Stephen R. Palmer Subsequent Roles

Moment-Intervals get the Blues Missing from the original DNC in 1999 Pink Classes can have Descriptions just like Greens

Whole-Part Relationships

Color Differences Can Be OK (A) This model has a whole-part color conflict but it is not wrong. It is simply less flexible and more coupled (B) This model resolves the color conflict and is more loosely coupled but requires 2 more classes

Just Plain Wrong Some color combinations in Whole-Part relationships should immediately raise the red flag for the modeling team As a general rule, question all aggregation and composition where color changes across the association

Subsequent Blues Description classes can have object inheritance relationships with subsequent descriptions Generally, there will only be one green class in the chain. Greens may aggregate or collect other greens but object inheritance should be yellow- green, green-blue or blue-blue

Class or Object Inheritance Courtesy Stephen R. Palmer

Simple Corporate Structure Example

Types of Blues Blue Catalog Descriptions, but also Enumerations and encapsulated (plug-in) Business Rules Each rule can have its own interface plug-in point and implementors can be hooked in at runtime

Putting It All Together

Law of Demeter A different view of the DNC showing the dynamic dependencies between classes. Classes only hold dependencies to their immediate neighbors The DNC is very loosely coupled

LoD Compliant Sequence Diagram

Wrong – not LoD Compliant

Possible Component Boundaries

DNC as Component Model

A sequence of > can be packaged together as a component Business Workflow Example Component Boundary

Re-usable Enterprise Components Pinks and yellows are re-usable across multiple greens – the core Enterprise Components Greens and blues are re-usable across discrete Enterprise Applications modeled as sequences of pinks

Two more possible schemes

One-way Dependency

Resolving 2-way Dependencies

More 2-way Dependencies

Easily learned - Easily taught But yet, a craft - perfected over time DNC is reliable and repeatable - a basic pattern even novice modelers can follow Archetypes easily identified from requirements documents Eliminates class discovery problems Leads to elegant, robust, extensible, agile models Take-away modeling rather than addition Typically an order-of-magnitude speed improvement for class diagrams over traditional verb-noun approach Only one pattern to learn! Summary – Color Modeling

Questions?

Contact Details David J. Anderson Program Manager, Microsoft

Object Models : Strategies, Patterns & Applications, 2nd ed., Coad, Mayfield & North, Yourdon Press, Prentice Hall, 1997 Java Modeling in Color with UML : Enterprise Components and Process, Coad, Lefebvre, De Luca, Prentice Hall, 1999 Data Model Patterns : Conventions of Thought, David Hay, Dorset House, 1996 The Coad Letter #68 - The Domain Neutral Component, Stephen R. Palmer, The Coad Letter #71 – From Association to DNC, Stephen R. Palmer, The Coad Letter #74 – Historic Values, Stephen R. Palmer, The Coad Letter #76 – Modeling User Roles, Stephen R. Palmer, The Coad Letter #77 – Object Models to DNC, Stephen R. Palmer, The Coad Letter #79 – The Example Teaches, Stephen R. Palmer, The Coad Letter #82 – Description Class Archetype, Stephen R. Palmer, The Coad Letter #87 – Good Ideas Behind Color Modeling, Stephen R. Palmer, The Coad Letter #103 – Party Time, Stephen R. Palmer, The Coad Letter #107 – Party Time: Modeling Legal IDs, Stephen R. Palmer, References