Bernard Szlachta: /* Business Rule Approach */

2014-10-31T14:23:09Z

Business Rule Approach

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{{Cat|OCEB B200.6 - Business Rules}}
{{Cat|OCEB T200.4 - Business Rules}}
{{Cat|Drools|001}}
{{OCEB Links}}
{{Cat|Business Rules}}
Sources:
# Business Rules Concepts, Third Edition, by Ronald G. Ross
# Principles of the Business Rule Approach, by Ronald G. Ross

If not stated otherwise, quotes in the presentation below come from this book.

<slideshow style="nobleprog" headingmark="⌘" incmark="…" scaled="false" font="Trebuchet MS" >
;title: Business Rules Approach
;author: Bernard Szlachta (NobleProg Ltd)
</slideshow>

== Business Rule Approach ⌘==
https://docs.google.com/drawings/pub?id=1qnh1m5sS4qSZOMxu4jhu9LDxfr1X5b3B4baxFfR6dr0&w=960&h=720&.png

== Business Operations vs Human Body ⌘==
* Structure - bones - '''fact model'''
* Power - muscles - '''business processes'''
* Control - nervous system - '''business rules'''

== Relations Rules, Processes and Fact Model ⌘==
All three are:
* essential (cannot work on their own)
* interconnected (integrated)
* specialized (one role)
* nervous system is the most important

== Structure ⌘==
Fact Model (complete skeleton):
* Definition (shape of the bone)
* Term (standard name)
* Wording (ligament)

== Power ⌘==
* Provided by Processes
* Processes "do what the business needs to get done"

== Control ⌘==
* Provided by business rules
* Rules constrain procsses

=== Fact Model ⌘===
* Provides the structure
* "Basic things we can know in common about the business"
* "Collective or shared know-how"

=== Term ⌘===
"a word or expression that has a precisely limited meaning in some uses or in peculiar to a science, art, profession, trade, or special subject"
Merriam-Webster

Term should be:
* Basic (cannot be derived)
* Countable
* Non-procedural

E.g. Customer, Employee, etc...

=== Fact Type ⌘===
* compared to ligament
* noun-and-verb constructions
* used in business rules
* "recognizes something that can be known"
* in SBVR: meaning of the predicate
e.g:
* customer '''places''' order (can be used in a rule: "A customer has always placed at least one order"

= Fact Type and UML Class Diagram ⌘=
* Fact Model can be translated into UML Class Diagram
* Fact Model is created in order to write rules (from business perspective)
* UML Class diagram is more general concept
"The principal deliverable of fact modeling is a business vocabulary, not a diagram"

== Business Rules ⌘==
* "A business rule is a rule under business jurisdiction"
* Criterion for making decisions
* Restrict the choice (constraint)
* Must be predictable

== Rules, facts, terms and concepts ==
; "Rules build on facts,
; and facts build on concepts as expressed by terms.
; Terms express business concepts;
; facts make assertions about these concepts;
; rules constrain and support these facts.”

== Rule Types ⌘==
* '''Behavioural''' Rules (you can break it) ([[SBVR]]: '''Operative''' Rules)
** e.g. Every employee must sign employment agreement
* '''Definitional''' Rules (cannot be violated directly) (SBVR: '''Structural''')
** Associate Trainer is a trainer who signed Associate Trainer Agreement
** Premium Customer is a customer who orders more than $1mln in a calendar year

Definitional Rules can change, definitions do not change

== Rules and Events ⌘==
* Event is something that happens
* Events should NOT be mentioned in a business rule
* Business rule can be triggered by many events
** Usually it is at least 2 events
** e.g. Order must be greater than $100

== Rule Independence ⌘==
* Separating business rules from processes
* Rules independent from each other
* Rules independent from events

== Enforcement Levels ⌘==
* Define how we respond to rule violation
* e.g. strictly enforced, deferred enforcement, post-justified override, guideline, etc... (compare BMM)

== Rule Categories ⌘==
# Rejector (Constraint)
#* Order total amount must be greater than $100
# Producer (Production Rules)
#* Early Booking discount is calculated as 5% of total order
# Projector (Event Rule, Stimulus/response rule)
#* If the invoice is overdue, send a reminder to the customer

== See Also ⌘==
* http://www.businessrulesgroup.org/brmanifesto.htm

== Exercise ⌘ ==
# For a Pizza Company, create a fact model
# Write a couple of rules a Pizza Company can have based on the fact model
[[Pizza Rules Sample Answer]]

Business Rules Approach - Revision history

Bernard Szlachta: /* Business Rule Approach */