Melbourne agile and scrum sig slides v01-00

Country Endeavours“Creative Solutions for Difficult Problems”

© 2012

1(John Giles)

The civil (uncivil?) war-

Agilist vs. Data Architect

1. Understand the “enemy”2. The mechanics of data pattern agility3. Tips & techniques4. Take-aways for you


© 2012

2

What’s the war really about?

© 2012Country Endeavours

“Creative Solutions for Difficult Problems” 3

Competing views Agilists

• Can’t wait for perfect design – miss the opportunity• Don’t need perfection – achieve better via iterations• Standards may reflect “old” – we can do better• Hence opinion “We don’t need no … architects”

(Or at least the old-style ones) Architects

• “Integration” technical debt - Speedy delivery of solutions = speedy delivery of integration problems

• Concern over “architecture breakers”


“Creative Solutions for Difficult Problems”

Conflict resolution(“fighting over the remote”)

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The vision for a creative win-win

A start-up data architecture/model• Based on proven patterns• Assembled in days. Or even hours!

Flexibility over successive iterations• Start-up was minimal, but patterns extensible

Simpler post-project integration (if required)• If all enterprise data artifacts are built on common

patterns, integration-made-easy (almost)

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“Patterns” - elegance today, flexibility tomorrow.

Gamma et al: “Strict modeling of the real world leads to a system that reflects today’s realities but not necessarily tomorrow’s. The abstractions that emerge during design are key to making a design flexible”

Ambler: “Many agile developers underestimate the value of data modeling and other data skills at their peril … and have foregone opportunities for even greater productivity and quality.”

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Modelling controversies

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I’ve been challenged!!!

Three projects about to kick off All needed to be subsequently integrated, via

an enterprise data model (EDM) Competitor’s EDM took 5 years of effort My allowance – 10 days effort Solution: Len Silverston

• Len Silverston’s 50% to 75% theory• Time-boxed interviews• YAGNI (75% fit OK)

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© 2012

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Mechanics of patterns



Fine-grained “Elementary patterns”

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namedateOfBirth

Person

skillTypeCodeskillTypeDescription

SkillType

0..* 0..*

skill acquisition

namedateOfBirth

Person

skillTypeCodeskillTypeDescription

SkillType

dateAcquiredlevelOfProficiency

PersonalSkill

1 0..*

personal skill record 1

0..*

skill inventory


“Creative Solutions for Difficult Problems” 11

Resources & their attributes

registrationNumberfuelTypenumberSeats

FourWheelDriveCabChasis

waterCapacitypumpDeliveryRatefuelType

SlipOnTank

radioTypemakemodel

Radio

0..1

0..1

current fitting

0..1

1..2

emergency communications

registrationNumberwaterCapacityairSpeed

WaterBomber0..1

2..2

communications



Using the EAV Elementary pattern

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resourceSpecificationNameisAbstract

ResourceSpecification

resourceTypeCoderesourceTypeDescription

ResourceType

0..10..*subclassification

10..*

classification

effectivePeriodresourceName

Resource

0..1

0..*inheritance

1

0..*

template

localNameminOccursmaxOccursderivationExpression

Utitilty-EAV::AllowableAttribute

1

0..*

containment

specifiedValue

Utitilty-EAV::AttributeValue

Note that components of this Assembly Patternare based on the Entity/Attribute/Value (EAV)Elementary pattern (also known by severalother titles e.g. the "Name/Value pair" pattern).

attributeNamedatatype

Utitilty-EAV::AttributeSpecification

1

0..*

containment

1

0..*

constraint

1

0..*

specification

unitOfMeasure

Utitilty-EAV::EnumerationItem

1

0..*

containment

effectivePeriodresourceIdentifierTyperesourceIdentifierValue

ResourceIdentifier

1

0..*

identification

enumerationValue

Utitilty-EAV::DiscreteEnumerationItem

minimumValuemaximumValueminimumBreakRulemaximumBreakRule

Utitilty-EAV::RangeEnumerationItem

0..1

0..*

enumeratedValue

effectivePeriod

ResourceToResourceRelationship

1

0..*

participant1

1

0..*

participant2

resourceToResourceRelationshipTypeCoderesourceToResourceRelationshipTypeDescriptionparticipant1Roleparticipant2Role

ResourceToResourceRelationshipType

1

0..*

classification

1

0..*

participant type1

1

0..*

participant type2



One medium-grained pattern- the face of “Party”

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namegender

Person

registrationNumberregisteredName

Organization

effectivePeriod

Party



Drill-down for “Party”

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effectivePeriodnameDisplayString

Party

effectivePeriod

Role

10..*

fulfilment

roleTypeCoderoleTypeDescription

RoleType

10..*

classification

gender

Person Organization

effectivePeriodaddressUsageType

AddressService

effectivePeriodaddressDisplayString

Address

postalDeliveryDescriptiontownstatepostcodecountry

PostalAddress

flatIdentifierfloorIdentifierpropertyNamelocationDescriptionstreetNumberstreetNametownstatepostcodecountry

PhysicalAddress

countryPrefixareaPrefixlocalNumber

PhoneNumber

emailAddressString

Emailddress

1

0..*

(link)

effectivePeriodpersonNameTypesalutationfamilyNamepostNominal

PersonName

givenNamesequenceNumber

PersonGivenName

effectivePeriodorgNameTypeorgName

OrganizationName

11..*

containment

10..*

containment

1

1..*

containment

partyIdentifierTypepartyIdentifierValueeffectivePeriod

PartyIdentifier

1

0..*

identification

1

0..*

(link)



A palette of “Assembly patterns”

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Party & Role

Event

Account

Location

Document

AgreementTask

Product

Resource / Asset



Coarse-grained “Integration patterns”

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2

Party & Role

Event

Account

Location

Document

AgreementTask

Product

participates in,signatory to, ...sited

at

copyfiledasconstrained

by

Resource / Asset



Or mineral exploration/extraction

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Party & Role

Event

Account

Location

Storableobject /

document

AgreementTask

Product

participates in,signatory to, ...sited

at

archivedat

associatedwith

copyfiledas

used as basisfor analysis in

constrainedby

Resource / Asset generates analysis

results held as



… what about emergency response?(or your problem?)

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Party & Role

Event

Account

Location

Document

AgreementTask

Product

Resource / Asset



(a possible solution framework)

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Party & Role

Event

Account

Location

Document

AgreementTask

Product

based at,now at, ...

occursat

occursat

triggers

assignedto

sitedat

associatedwith

manages,owns, ...(or "is")

Resource / Asset


© 2012

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Tips-&-techniques for using patterns



“In general, generalise”

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namedateOfBirth

Person

registrationNumberregisteredName

Organization

Party

effectivePeriod

Role

roleTypeCoderoleTypeDesc

RoleType

1

0..*

fulfilment

1

0..*

classification

agreementReference

Agreement

0..*

0..*cross-reference

2..*

0..*involvement

licenseNumber

Solicitor

registrationNumber

RealEstateAgent

agreementTypeCodeagreementTypeDesc

AgreementType

1

0..*

classification

loanToValueRatio

Mortgage

partyTypeCodepartyTypeDesc

PartyType

0..1

0..*

classification



Use patterns beyond their intended purpose

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itemIdentifieritemDescription

GoodsItem

quantityRequired

AssemblySpecificationItem

1

0..*

aggregation rule 1

0..*

usage rule

partyIdentifierpartyName

Party

shareholdingPercent

Shareholding

1

0..*

aggregation rule 1

0..*

shareholding recording



Tailored extensions become a pattern

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contactReasonCodecontactReasonDescription

ContactReasoneffectivePeriodnameDisplayString

Party

effectivePeriod

ContactRuleSet

0..1

0..*

constraint

ContactRuleStep

0..1

1

initial step

0..1

0..1subsequent step

effectivePeriodaddressUsageType

AddressService

1

0..*

(link)

1

0..*

rule target contact point

effectivePeriodincludeOrExcludeIndicator

ContactRuleFilter

1

0..*

restriction on use

timePeriod

TimeOfDay

dayRange

DayOfWeek

dateRange

CalendarPeriod

effectivePeriodstatus

Role

1 0..*

fulfilment

0..1

0..*

generic constraint

0..1

0..*

specific constraint

effectivePeriodaddressDisplayString

Address

10..*

(link)



YAGNI(You ain’t gonna need it)

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Sliding door panel (glass)

Side jamb

Door side

Towell bar

Fixed panel bottom

Door top

Door bottom

Fixed panel (glass)

Fixed panel top

Fixed panel side

Head rail

Bottom rail

Model Num.

Variable Number

Acronym Operand 1

Operator Operand 2

20 5 BR WB minus "7"

20 6 SJ H minus “35”

modelNumbermodelName

Model

variableNumbervariableAcronymvariableName

Variable

Measurement

operand1operatoroperand2

Computation

1

0..*

containment



Take the enterprise view(& challenge the concepts)

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nameaddressphone

Party - Simplified

salarysuperannuationFund

EmployeeRole

creditLimitindustryCode

CustomerRole

effectivePeriod

Role

effectivePeriodnameaddressphonesalarysuperannuationFund

Employee

effectivePeriodnameaddressphonecreditLimitindustryCode

Customer1

0..*

fulfilment



The “T-model” approach

Mile-wide, inch-deep (touch points at least) Drill-down only where required Iterate within project, & across projects

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Account Agreement Document Party/Role (etc.)

High-level logical subject areas

Standard logical assembly patterns

Refined logical assembly patterns



Does it really work?

Some real-life stories• Weeks, not months, for a usable framework

But• It’s more of a framework than an implementation

design• The 80/20 rule doesn’t work

Even with “patterns”, there is a place for (agile) modellers!!!

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Messages for modellers?

The Agile world is different:• Modelling “ain’t enough” • Deliver early, stay to refine, integrate at end

There’s a need to learn about:• “Agile” (Scrum, Kanban, Lean, stand-ups, UX, …) • Patterns, and their integration• OO – More than reading UML

It can be fun working with agilists

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Messages for agilists?

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Welcome (agile) modellers, & be patient Jointly identify/mitigate “architecture breakers” Help “data” types with solutions beyond patterns Tell “data” types your expectations:

• Want a framework in your first iteration (not perfect, but it should be robust, extensible)

• They need to keep an eye on integration – it’s their job



Conclusion?

Start-up models?

Flexibility over successive iterations?

Simpler post-project integration ?

… and any questions?

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Melbourne agile and scrum sig slides v01-00

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