Britz_BusinessRules_20080924

8/8/2019 Britz_BusinessRules_20080924

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Camilion Solutions, Inc. All Rights Reserved. ProductAuthority, Authority Suiteand related trademarks are property of Camilion Solutions, Inc.

Factoring Business Rulesinto Requirements Analysis

Mario Britz, Camilion Solutions, Inc.

First presented on September 24, 2008 at theIIBA Toronto Chapter

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Question 1

a) 5 years

b) 10 years

c) 20 years

d) Good software never expires it justgoes to a better place

The average lifespan of enterprise software is__ years.


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Question 2

a) New technology

b) Changing requirements

c) Improving performance

d) Just because

The majority of legacy replacements areattributed to _____________.

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Objectives

Understand the nature of business rulesand how it influences the choice ofimplementation

Discuss ways the BA can better expressbusiness rules (with examples)


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The Business Rule Motivation Model

Source: Business Rules Group

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The Product/Process Matrix


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Variability

How far apart is your simplest and mostcomplex products?

To what extent does the product affect theprocess?

How frequent are rule changes?

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Implementation Options

Policies cancelled after 30 days ofcontinuous coverage are subject to a $50administrative fee.

Source: Ultrapak Underwriting Guidelines


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Option Comparison

a) if daysInEffect > 30then cancellationFee = $50else cancellationFee = $0

b) if daysInEffect > getMaxFreeDays()then cancellationFee = getCancellationFee()else cancellationFee = $0

c) cancellationFee =executeRules(Cancel, Today())

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Implementation Choices

Increasing Volume

Increasing Variety

Hard coded(ifthenelse)

Data DrivenBusinessRule Driven

Increasing Flexibility & Configuration

Increasing Performance & Effort to Change


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Business Rules within Context

Strategy provides high-level direction about whatactions an organization should take to achieveits goals

Actions involve producing one or more productsby following a set of business processes

Product rules guide composition

Process rules guide behavior

Enforcement levels apply

Variability influences the choice ofimplementation

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The Voice of the Customer

Business people express rules in naturallanguage

Imprecise and open to interpretation

No separation of process and product


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The Case for Modeling

If you cant model the problem then youmost likely dont understand it

If you dont model the problem then youmost likely dont know what you dontknow

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Example 1

All plans require 100% participation ofeligible employees and a minimum of 3employees must be insured for all quotedbenefits. Minimum monthly premiumrequired is $100.

Source: Benepac Underwriting Guidelines


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What We Dont Know

Plan

minPrem

Employee

isMember3..n1

Is there a maximum # of planmembers?

Can an employee be associatedwith more than one plan?

Does the minimum premiumapply to an individual member orthe total plan premium?

What determines eligibility?

How are benefits assembled intoa plan?

How do the rules change overtime?

AssumptionsGaps

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A Better Understanding

PlanminMonthlyPremPerMemberminFullMembersmaxMembers

Employee

dateOfBirth/age

1..n

Age determines eligibility

A maximum exists and both minimum and maximummay change over time

An employee may participate in different plans over time

The monthly premium is on a member basis

/isMember/isFullMember

n

Benefit

n

1..n

n

n


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Example 2

The employee organization which receivesa majority vote of the employees in arepresentation election is the onlyemployee organization having the right torepresent the employees before the boardof directors of the district.

Source: Washington State School Board

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Limited Flexibility

SchoolDistrict

CollectiveBargainingUnitEmployee0..1n

1..n

1

1..n

1 majority

Very explicit relationships Limited expansion opportunities


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Abstraction

Party1..n

highest degree of flexibility

more difficult for business to understand

difference between conceptual and specificationmodels

relationship1..n

PersonOrganization

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Example 3

A novice driver whose license has beenexpired must reapply as a new driver andpass the required tests (vision, knowledge,road tests).

Source: Ontario Motor Vehicle Registration


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What We Dont Know

Driver11

Licence

expDate

ExperienceLevel

1

n

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A Better Understanding

Driver1..n

The experience level of a driver varies within the

context of the particular licence

1Licence

expDate

DriverHistory ExperienceLevel1n


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Embedded Rules

expired?

renew

novice? renew

reapply

reapply

vision?

apply

knowledge? issueroad?

[fail]

[pass][pass][pass]

[fail] [fail]

[yes]

[no] [yes]

[no]

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test

Abstraction

status?

renew

experience? renew

reapply

reapply

vision?

apply

knowledge? issueroad?

[fail]

[pass][pass][pass]

[revoked]

[else]

[novice,intermediate]

[else]

3 attempts within a 2month period with atleast 1 week inbetween


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issued

Aligning Product and Process

pending/apply

active[approved]

[declined]

expired

[experienced]/renew

expire

[novice]/reapply

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One Ring to Bind them All

Use case serves to complete the picture

Aligns all models

Facilitate expression of business rules atlowest level of granularity

Further helps to identify gaps


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Use Case Notation

5. Sets the status of thelicence to ACTIVE

The Use Case Ends

4. Updates the expirationdate to 5 years fromToday

ReapplyAF3. Verifies that the driverexperience level is notNOVICE

Not expiredEF2. Verifies that the licenceexpiration date is in thepast

1. Requests renewal

ReferenceSystemActor

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Abstraction (Use Case)

LifecycleSD4. Updates the licence

statusThe Use Case Ends

Renewal termBR3. Updates the licenceexpiration date

Renewaleligibility

Do not renew

Reapply

BR

EF

AF

2. Verifies that the licencecan be renewed

1. Requests renewal

ReferenceSystemActor


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Abstraction (Business Rules)

1. Five years from date of renewal2. Renewal Term

1. Expiration date must be in the past

2. Driver experience level must not be novice

1. Renewal Eligibility

DescriptionName

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Rule Types and Means of Expression

Data requirement grids (including datatypes, default values, validation rules,error messages)

Formulas (calculations)

Decision tables (eligibility, cross-validation,outcomes)

Single values (data driven configuration)


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Applicability

Agile High levels of change from iteration to iteration

Models document the implementation

Abstraction absorbs impact

Product Configurators Same set of use cases

Same process and product models

Business rule driven configuration

Maintenance Model based impact analysis

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Expressing Rules through Models

Product structure rules can be representedby static models such as the UML classdiagram

Process rules can be represented bydynamic models such as the UML activitydiagram

UML state diagrams partially bridges thegap between process and product

Use cases serve to complete the picture


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References & Further Reading

Software Lifetime and its

Evolution Process overGenerations [Tamai]

Enforcement of Business Rules

in Relational Databases UsingConstraints [Zimbro]

White Papers

Principles of the Business Rule

Approach [Ross, 2003]

ISBN 0201788934

Analysis Patterns: Reusable

Object Models [Fowler, 1997]

ISBN 0201895420

Design Patterns: Elements ofReusable Object-oriented

Software [Gamma, 2004]

ISBN 0201633612

Uml Distilled: A Brief Guide tothe Standard Object Modeling

Language [Fowler, 2003]

ISBN 0321193687

Books

www.businessrulesgroup.org

Links

Documents

Britz_BusinessRules_20080924