=Paper= {{Paper |id=None |storemode=property |title=Semantic-ontological Combination of Business Rules and Business Processes in IT Service Management |pdfUrl=https://ceur-ws.org/Vol-799/paper5.pdf |volume=Vol-799 |dblpUrl=https://dblp.org/rec/conf/ruleml/SellnerSZ11 }} ==Semantic-ontological Combination of Business Rules and Business Processes in IT Service Management== https://ceur-ws.org/Vol-799/paper5.pdf

Semantic-ontological combination of Business Rules and
Business Processes in IT Service Management

Alexander Sellner1, Christopher Schwarz1, Erwin Zinser1
1
FH JOANNEUM University of Applied Sciences, Department of Information Management
Alte Poststrasse 147, 8020 Graz, Austria
{Alexander.Sellner|Christopher.Schwarz|Erwin.Zinser}
@fh-joanneum.at

Abstract. IT Service Management deals with managing a broad range of items
related to complex system environments. As there is both, a close connection to
business interests and IT infrastructure, the application of semantic expressions
which are seamlessly integrated within applications for managing ITSM
environments, can help to improve transparency and profitability. This paper
focuses on the challenges regarding the integration of semantics and ontologies
within ITSM environments. It will describe the paradigm of relationships and
inheritance within complex service trees and will present an approach of
ontologically expressing them. Furthermore, the application of SBVR-based
rules as executable SQL triggers will be discussed. Finally, the broad range of
topics for further research, derived from the findings, will be presented.

Keywords: Semantic IT Service Management, SBVR-based SQL statements,
Ontological ITSM service trees

1 Introduction

IT Service Management (ITSM) can be seen as a large and complex environment
for business processes and rules with a certain potential for automation. On the one
hand, ITSM puts a strong focus on providing tools for managing business topics such
as outsourcing costs, licensing fees and negotiated prices within Service Level
Agreements (SLAs), on the other hand the goal is to provide clearly defined processes
for managing IT resources, which are, for instance defined in the ITIL framework [1].
Having a look at ITSM from large IT service providers’ perspectives, there is an
tremendous amount of so-called configuration items which are combined together to
services, which are ultimately sold to clients. Due to changes in system environment
or technological development, these services are in a constant state of change, turning
the task of outsourced service provision to a rather stable price to a quite difficult
challenge.
Most ITSM activities affecting existing relationships between IT service providers
and their clients are triggered by so called “requests for changes” (RFCs). RFCs
usually add, remove, or change existing services e.g. upsize the RAM of a server or
add an SLA to a database application. Almost every ITSM item will have a certain
dependency to another ITSM item and, depending on the complexity of the services,
these relationships will lead to the formation of a so-called service tree. The service
tree can be seen as one or more graphs, as there is no single parent node and items,
such as SLAs can exist multiple times.
A well-suited approach for making such graphs human-readable is to make use of
ontologies using semantic expressions [2]. By applying ontologies, it becomes
possible to create graphical representations of the complex service trees, making it
possible to discover all dependencies and to keep them well-managed. A further
advantage becomes obvious, having a look at natural-language based semantic
expressions used by ontologies. Besides adding further advances to the
comprehensibility and integrity of service trees, this also creates the possibility of
performing commonly understandable modifications of service relationships and
therefore can help to create a mutual understanding between ITSM service providers
and their customers [3].
Because of the strong business connection and great involvement of rules within
SLAs, the idea of establishing a rule repository for service level definitions which are
based on natural language, seems obvious. Over the last years, several standards for
such definitions have been created such as RuleSpeak1, R2ML2 and Semantics of
Business Vocabulary and Business Rules (SBVR)3. Most recently, it seems that there
is a strong support for the SBVR standard both within the academic community as
well as the industry.
This paper focuses on the challenge of displaying complex graphs of service
relations to human-readable ontologies, based on semantic models. Furthermore the
paper will discuss on the special topic of enriching these complex service trees with
SLAs assembled by SBVR-based business rules. Another topic being discussed will
be the establishment of SBVR-based business rules using DBMS triggers for
execution [4].
The paper is structured as follows: Section 2 will have a closer look at service
trees, discuss the paradigm of service inheritance and present ways of ontologically
displaying existing service structures. Section 3 will explain the main categories of
SLA rules within service trees and present samples for converting SBVR definitions
to database-executable statements. Section 4 will discuss topics for further research
within the presented areas.

1
www.rulespeak.com/
2
http://rewerse.net/
3
http://www.omg.org/spec/SBVR/1.0/

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2 Establishing ontological views of service trees based on
existing semantic definitions

As already briefly discussed in the previous section, the structure of service trees in
real-world business environments can be quite complex and is therefore hard to
handle and maintain by people carrying out various tasks within ITSM processes. The
following example will provide closer insights into the process of establishing RFCs
as well as the related legacy data and the necessary procedures to involve ontological
views which allow establishing a well-structured perspective on the configuration
items’ relationships and corresponding inherited attributes.
Within the given case, which is based on a project carried out for a large ITSM
provider, the following types of configuration items (CIs) can be identified:
• Service: A service is a collection of ITSM assets with a business-relevant impact.
This means that they are the elementary constructs within contracts between
service providers and customers. Having a look at the function of services within
the service tree, they can also be used as logical containers for putting together
various “low-level” services to more sophisticated “high-level” services.
Therefore, a low level service can for instance be a domain name resolution service
and a high level service could be a billing application. As a matter of fact, services
can exist multiple times within the service tree.
• Host: Hosts are the fundamental basis for establishing services. As a result, a
service can be put together by one or more hosts. Because of a strong advance in
virtualization technology over the recent years, hosts don’t necessarily need to be
actual hardware but multiple hosts could also depend on a host-service relationship
providing the actual hardware for virtualization as well as on an additional host-
service relationship for data storage. The same host can be used by multiple
services and therefore can appear multiple times within the service tree.
• Service Level Agreement: SLAs include legal implications regarding the quality of
services. For instance, the loss of an email service for a certain time could have a
significant business impact for organizations. As a result, SLAs also handle penalty
fees which need to be paid under certain circumstances. This can, for instance, be
as soon as a service becomes unavailable (first failure fines and concurrent failure
fines) or if a certain value for the availability of a service over a certain period is
not met (availability percentage per day, month or year). SLAs follow the principle
of inheritance and are therefore valid for all services or hosts which are
hierarchically subordinate within the service tree. In addition, SLAs can appear
multiple times within the service tree and they need to be prioritized in order to
prevent discrepancies by allowing only one valid SLA per host or service.
• Maintenance Contract (MTC): MTCs contain contractually defined regulations
regarding repair and renewal tasks on hardware. This can for instance be the
replacement of a defect part or the regular upgrade to newer hardware parts. MTCs
can be closed for services or hosts have the same characteristics as SLAs regarding
inheritance. In contrast to SLAs, there can be multiple MTCs valid at the same
time for one service or host which leads to accumulated maintenance liabilities.

35
Besides these CIs, there can be a wide range of additional CIs involved in real-
world ITSM processes [5]. The above-mentioned items will serve to establish a
simplified demonstration of a sample ITSM service tree which already contains a
great variety of characteristics worth to undergo closer investigation. The sample
service construct is demonstrated in Figure 1.

Figure 1. Sample ITSM service construct

The sample demonstrates two RFCs with their respective hierarchically
subordinate services, hosts, SLAs, and MTCs. RFC1 might, for instance, be a
database service hosted on a virtual machine (HOS1) with HOS2, HOS3 and HOS4
being redundant database servers, each having different SLAs. RFC2 could be a Web-
based application consisting of SVC4 as database backend and SVC5 as Web servers,
whereas SVC4 consists of two machines (HOS2 and HOS4) already being used by
RFC1.
Considering the characteristic of inheritance for SLAs and MTCs within service
trees, the example clearly illustrates why more complex service trees are almost
impossible to manage and handle from a business perspective.
Having a look at the SLAs in RFC1, it clearly needs to be determined whether
SLA1 or one of the respective SLAs for HOS2, HOS3 and HOS4 is valid. This is a
prime example where priorities need to be assigned to SLAs in order to ensure legal
correctness and optimized business benefit. Such a prioritization even needs to be put
in place across boundaries of RFCs. For instance within RFC2 it also needs to be
determined whether SLA4 or SLA2 and SLA5 respectively are valid for HOS2 and
HOS4. Changing priority of SLA2 or SLA4 would again have an impact on the
overall situation of RFC1
When focusing closer on the question of how prioritization between two SLAs
needs to be done, it becomes clear that sometimes it is quite difficult to say which
SLA is preferable to be applied . Assuming that within RFC1, the fines for first failure
are higher in SLA1 than in SLA2 and the availability fines are higher in SLA2 than in

36
SLA1, it is impossible to instantly determine the most cost effective solution. It is
rather imaginable that the availability of service or hosts is monitored over a certain
period leading to statistical forecast regarding its behavior. Only then it would be
possible to pick the optimal SLA, taking all types of fines into account.
In contrast, the challenge regarding MTCs is rather on deciding whether individual
MTCs should be discharged because of redundancies or existing MTCs should be
extended. As a result, the accumulated MTC benefits should be considered for every
individual host or service.

3 Invoking semantics within ITSM service trees

To overcome the challenge of managing complex relations within ITSM service
trees, it seems quite obvious to introduce ontologies and semantic expressions. This
makes it possible to display dependencies between configuration items in a human-
readable way and supports extending or rearranging the service tree [6]. An example
of such an ontological view taken from the prototype of an ITSM application of a
large IT service provider is given in Figure 2. The figure displays an RFC which is
linked to an SLA, an MTC, a hardware asset and a high level infrastructure service
which is then linked to a low level infrastructure service. The figure also reveals the
concept of service instances used to express configuration items which appear
multiple times within a service tree.

Figure 2. Ontological view of ITSM service tree

Integrating semantic expressions, adds a further level of complexity regarding the
underlying data structure [7]. This can lead to quite a heavy integration effort
regarding database design and operations performed to read, write or update data.
On the other hand, the advantages for integrating semantic expressions are
obvious. It becomes possible to create human-understandable illustrations of service
trees based on natural language. Additionally, rules can be applied on the service
structure based on the existing semantic expressions. Consequently, these rules can
contribute to handle the situation regarding SLA and MTC inheritance within the
service tree.

37
4 Integrating SBVR-based rules using DBMS triggers for
execution

In general, three categories of rules can be identified within ITSM service trees:
1. Rules to prevent adding new SLAs or MTCs due to inconsistencies or
disadvantageous business impacts
2. Rules to analyze and improve existing SLA and MTC structure
3. Rules within SLAs themselves
There are various ways following the goal of achieving a loosely coupled
execution of these SLA rules within a repository on the specified service tree. A quite
feasible approach is to aim for rule execution within Database Management Systems
(DBMS) using SQL triggers. This approach leverages characteristics of DBMS to
establish as rule engines allowing the execution of Event-Condition-Action (ECA)
rules [8].
Recent findings dealing with the conversion of SBVR definitions to SQL
statements were taken as basis for developing a prototype making it possible to
express the first category of rules for SLAs in structured English and carry out the
respective database operations to put them in action [9,10].
Listing 1 gives an example for the conversion of the first category of rules from
structured English to an ECA rule which is placed on the DBMS.

Structured English statement:
T:SLA
T:SVC
T:total fines
F: SLA has total fines
F:SLA is linked to SVC
NR: For an SLA that is linked to an SVC it is obligatory that
the total fines of the new SLA are less than the total fines
of the old SLA.
SQL expression:
CREATE TRIGGER "NR1" BEFORE UPDATE OF “SLA_id”
ON "SLA-is_linked_to-SVC"
WHEN NOT
(SELECT "total fines" from "SLA" where id=new.SLA_id)<
(SELECT "total fines" from "SLA" where id=old.SLA_id)
BEGIN
SELECT RAISE(ABORT, ‘Requirement of NR1 not met’);
END;
Listing 1. Conversion from structured English to DBMS trigger statement

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The terms “SLA” and “SVC” and “total fines” are expressed as lines starting with
“T”. The fact types “SLA has total fines” and “SLA is linked to SVC” are marked by
a preceding “T”. Finally, the normative rule is denoted by “NR”.
Regarding the definition of fact types, the identification of table attributes takes
place using conjugations of the predicate “have” and a table relationship is established
by the predicate “being linked to”.
By choosing “NR” as markup, the creation of the SQL trigger is either based on a
fact type involving a relationship or on a table related to a single term. The
identification is based on the phrase being placed in front of the rule. If a fact type is
identified as input, the first term used to describe the identity column for the SQL
trigger.
Based on the fact type definition for the attribute “total fines”, the reverse order
“total fines of the new SLA” forms that basis for the SELECT statement (SELECT
"total fines" from "SLA" where id=new.SLA_id), whereas the definitions “new” and
“old”, are explicitly required because of the targeted syntax of the SQL trigger.
Because of the fact that the trigger should not abort when the defined rule is met,
the WHEN clause needs to be followed by NOT in order to display an error message
in any other cases.

5 Conclusions and Future Work

The approach presented, shows the advantages and challenges regarding the
application of ontologies and semantic expressions. Findings derived, led to
conclusions regarding prerequisites which need to be fulfilled, especially when
aiming for a close connection to underlying data structure.
Adding semantic expressions to ITSM service trees can increase presentability and
manageability. On the other hand, such an integration also implies a challenge
towards the underlying data, because of the paradigm of inherited SLAs and MTCs
within the service tree.
The application of SBVR based business rules adds further needs which must be
met by database models. In fact, the database design needs to be carried out in
accordance with naming conventions established within SQL statements converted
from SBVR.
Having a look at the originating statements defined in structured English, a
strongly controlled natural language needs to be applied in order to enable a
conversion to SQL definitions. The approach presented, focused on SBVR-based
rules for preventing negative business impacts in connection with the addition of new
SLAs. It needs to be investigated how these statements need to be verbalized for
MTCs. It will also be necessary to look at the conversion to stored procedures, which
would allow apply rules not only on a data manipulation level.
Further research will also be necessary to mathematically investigate paradigm of
inheritance within ITSM service trees. Most likely, this will be closely related to
graph theory and provide further insights how service trees can be optimized.

39
Another area worth performing research on will be investigating the application of
upper level ontologies within the specific scenario. This might lead to an enterprise
ontology for combining business processes and rules or to an ontology being closely
focused on the area of ITSM.

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