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IBM Research
7/3/2007 © 2005 IBM Corporation
Calculating the Business Importance of Entities in a Service-Oriented Enterprise
Amit Fisher [email protected], IBM ResearchFabiana Fournier [email protected] IBM ResearchDagan Gilat, [email protected], IBM ResearchGuy Rackham [email protected] IBM Global ServicesNatalia Razinkov [email protected] IBM Research Segev Wasserkrug [email protected], IBM Research,
IBM Research
© 2005 IBM Corporation2 7/3/2007
Agenda
� Problem description
� Solution approach
� Modeling a service – oriented enterprise
� Solution details for a service oriented enterprise
� Example
� Summary
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© 2005 IBM Corporation3 7/3/2007
Problem Description
� All major enterprises today require their business infrastructure to conduct business.
� The business infrastructure is composed of many components:
– Business level entities such as the business processes supported by the infrastructure and their corresponding Key Performance Indicators (KPIs).
– Mid level entities such as activities.
– Low level entities such as applications, hardware, etc.
� In many cases, it is essential to know the importance of each entity in the infrastructure in terms of units relevant to the business. Examples of such cases include:
– Decision making based on business importance: Investments regarding upgrades or replacement should be directed towards the components that are of utmost importance to the business.
– Monitoring and problem resolution scenarios: • Whenever a component fails, we need to be able to measure its importance in the sense of
what impact this failure will have on the business. • In the face of multiple failures, the problem that should be solved first is the one that
addresses the most important components.
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© 2005 IBM Corporation4 7/3/2007
Solution Approach
� Model the enterprise by modeling local dependencies between components– Local dependencies have defined types with associated semantics
• Examples: workflow, n out of m.– May have additional attributes associated with them E
• Example: Workflow patterns� Calculate standalone importance for all entities for which it is
(relatively) easy to do so– We denote this by Inherent Criticality or IC.
� Define a measure of importance (denoted Criticality) which enables taking into account global relationships between components– E.g. cycles in dependency diagram
� Define an algorithm for calculating the global measure– Based on the semantics of the local dependencies – Taking into account the IC
E
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Example 1
Business Process
Business Value = 20
Server
Requires
Business Process
Business Value = 20
Server
Business Value=20
Requires
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© 2005 IBM Corporation6 7/3/2007
Example 2
Business Process
Business Value = 20
Server1
Requires 1 of 2
Server2
Business Process
Business Value = 20
Server1
Business Value=?
Requires 1 of 2
Server2
Business Value=?
Business Process
Business Value = 20
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Modeling a Service Oriented Enterprise – Model components
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Modeling a Service Oriented Enterprise – Retail Banking Example
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Criticality Measure - Definition
� Determined by how the unavailability of entity A affects the unavailability of entity B
� Several definitions possible, fulfilling desired characteristics
� Definition:
– C(A) – criticality of entity A
– IC(B) – inherent criticality of entity B
– - probabilistic event denoting non availability of entity A
� � depends on
( ) ( ) Pr( | ) Pr( | ) ( )B A B AB AC A IC A F F F F IC B� � � � ��
AF
IBM Research
© 2005 IBM Corporation10 7/3/2007
Criticality Measurement Calculation - Algorithm Principles� A valid probability space must be defined
� Automatically derived from business dependency diagram– Bayesian Network created based on local dependency semantics– Required probabilities are calculated using the Bayesian Network
� Requires that probabilistic semantics be defined for each local dependency– Such probability semantics will be defined for each dependency type
� Bayesian Network constructed according to the following principles– A node in the Bayesian Network is created for each entity in the business
dependency diagram– An edge is created between every two nodes corresponding to entities which
have a local dependency between them• Direction of edge: To depending entity
– Conditional probabilities defined according to probabilistic semantics of local dependency
IBM Research
© 2005 IBM Corporation11 7/3/2007
Criticality Measurement Calculation - Algorithm
dependencyDiagram - The business dependency diagram( ) - The inherent criticality for each entity .
( )
entity
IC A ABN constructBayesianNetwork dependencyDiagram
A depende
/* Input*/
/* Algorithm */foreach ( ) ( ) ( , )
( ) 0
Pr( | ) Pr( , | ) Pr( | ) Pr( , | )
( ) ( ) Pr(
B BA A
B BA A
B
ncyDiagramC A IC A
calculateDependingEntities A dependencyDiagramB
IC BF F calculate BN F F
F F calculate BN F F
C A C A F
�
�
�
� �
�
foreachif
� �| ) Pr( | ) ( )BA AF F F IC B� �
endifendfor
endfor
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© 2005 IBM Corporation12 7/3/2007
Probabilistic Dependency Semantics – 1 out of 2 Example
Requires 1 of 2
Server2
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© 2005 IBM Corporation13 7/3/2007
Probabilistic Dependency Semantics – Workflow Example
E
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Credit Score Dependency Diagram
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Credit Score Example – Cont.
� Criticality value example: The windows 2003 server is the most critical component
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© 2005 IBM Corporation16 7/3/2007
Summary and Future Work
� The problem of calculating the importance of entities in a business infrastructure was defined
� A generic methodology for calculating this importance was defined
� An application of this methodology for the Service Oriented Enterprise was described
– A formal measure based on probability
– An algorithm based on Bayesian Network construction
� Future work
– Define other formal measures of importance
– Formally define desired characteristics of such measures• Formally define set of possible measures
– Improve importance calculation algorithm