Does service composition suffice to define business contracts for IT services in Networked organizations

DOES SERVICE COMPOSITION SUFFICE TO DEFINE BUSINESS CONTRACTS FOR IT SERVICES IN NETWORKED ORGANIZATIONSAUTHORS: ANTONELLA LONGO; MARIO A. BOCHICCHIO;BARBARA LIVIERI

PRESENTING AUTHOR: BARBARA LIVIERI ([email protected])

mailto:[email protected]

AGENDA

1) Context2) Objectives3) Our experience

a) Scenariob) Issues

4) Related works5) Service composition

a) Contractual Issues related to the feasibility of service compositionb) Contractual Issues related to service composition management

6) Conclusions and future works

CONTEXT

Service are becoming a pervasive element in the current economic scenario

Companies all over the world are interconnected with each other by service networks

The delivery of IT services (especially SaaS) to final customers requires the description of the service in end-to-end perspective, IT manager should be able to

map and monitor the whole IT service chain from the data center to the final user

end-to-end measurement of services

Barbara Livieri– The International ACM Conference on Management of Emergent Digital EcoSystems (MEDES 2013) – Luxembourg, October 28th – 31st

CONTEXT

IT Manager

Provider 1

Provider 2

Provider (…)

Provider n

Trade-off: cost or quality?

New services for final usersIT Department

static documents, signed by humans and enforced by law

• legal aspects;• terms:• obligations;• SLA• QoS• all relevant

functional and non-functional properties of the service

electronic documents orchestrating the interplay of human and automatic agents belonging to networked organizations

contract is subjected to constraints coming from the underpinning contracts

evaluation of inter-organizational aspects

OBJECTIVES

Obj: discuss some relevant open issues not covered by current Contract Management approaches and tools.

feasibility of service composition

how service levels limit and shape technical, legal and organizational aspects related to the contract of the composed service.

Service compositio

n

Feasibility Service levels

Legal aspects

Technical aspects

Organizational aspects


OUR EXPERIENCE - SCENARIO

MobEnt IT Service Provider7 year contracts

SLAs for availability and performance• 300 applications developed

in 30 years • wide variety of

architectures, technologies and domains

Evolution

IT Organizati

on

• more and more involved in the definition of business performance related to online business services;

• business services are conceived and designed as a composition of lower level services provided through different technological platforms

IT hardware and software

managersIT service managers

Temporary Group of Companies


OUR EXPERIENCE - ISSUES

Common issues Different languages and goals of IT

operators and business ones and they don’t interact with each other

Issues related to composed services

“How” to define and evaluate the target service levels related to component services, in order to attain a given Service Level (SL) for the business service;

Business Service

SLComponent services

SL1 SL2 … SLn

Accountability: which are the responsibilities, the penalties and the obligations for each operator?


RELATED WORKS Works on CM and SLM usually

take into account only automated agents in SOAs

nobody has still investigated how to model service chains taking into account stakeholders perspectives

In research literature the composition of services and the composition of contracts is largely investigated, but we haven’t found references about the issues of composing service level agreements, as defined in IT delivery contracts. We have also experienced that these issues are critical in enforcing service delivery contracts.Barbara Livieri– The International ACM Conference on Management of Emergent Digital EcoSystems (MEDES 2013) – Luxembourg, October

28th – 31st

Currently available CM and SLM methodologies are not sufficient as tools for effectively supporting large organizations in defining and managing contracts for online IT services and for their composition.

Not sufficient for automated SLA extraction and composition

because of: lack of stackeholders perspetives Lack of strategic and business aspects

Automated Agents

SOAs

SERVICE COMPOSITIONThe contractual issues that we are going to discuss regard both the feasibility analysis of

service level composition the aspects of service level

composition management in service contract enactment

We can distinguish two sets of issues some are blocking for service

level composition others must be checked but are

not blocking since they may produce only empty sets

Define service catalogue and service

accountability

Define service composition topology

Assess service level metrics and

measurement units

Assess service hours and calendar

Compare measurement period

Compare contact period

Define monitoring plan

Collect monitoring data

Apply service level composition rules

Analyze and report service levels of

composed services

Feasibility analysis of service level composition

Service level composition management



accountability



measurement units








composed services


Service level composition managementCONTRAC

TUAL ISSUES RELATED TO THE FEASIBILITY OF SERVICE COMPOSITION

SERVICE DEFINITION AND ACCOUNTABILITY

Services

Line of business

IT operations

Risk managem

ent

Contract managem

ent

Line of business

Service description

IT operation

s

IT infrastruct

ure

IT application

s

Risk manage

ment

Risks

Contract manage

ment

Contract

In order to compose services and to evaluate resulting SLs with related constraints, it is necessary to model them at the same level of abstraction

Service Catalog

Accountability is necessary in order to identify who manages the service and related service levels. Accountability imposes that all services deployed (regardless whether by human, machine or software) have the obligation to accept responsibility or to account for their actions.



accountability



measurement units








composed services




SERVICE COMPOSITION TOPOLOGY

According to the topology services are composed and service level specifications are calculated differently

Service 11

Node 10

Node 9Service

5Service

4

Node 8Service

1

Node 7Service

2Service

3

Service 6

Sequ

enti

al str

uctu

re

Parallel

structureConditional structure

Loop

structure



accountability



measurement units








composed services




Service visibility inside contracts

The decision is essential for contract owners in order to estimate the associated business risks of the composed service

SL metrics and measurement units

Values of SLAs are based on metrics;

In service composition, resulting service levels depend on composing service levels.

The necessary conditions for comparing them are that the metric is the same and the measurement units are compatible (e.g. measures must be related to time, or all measures must be percentages).

Black box: no internal details White

box: internal details fully exposed

Gray box: internal details partially exposed



accountability



measurement units








composed services




SERVICE HOURS AND CALENDAR

Example In the composition of services the

time window (and the service calendar) in which the composed service is guaranteed depends on the composing services. It defines the time and calendar the composed service level is guaranteed.

It depends on the topology and the homogeneity of services

If the composed service has an empty guaranteed window, the Service cannot be guaranteed

Service B

7 am – 11 pm

Service A

8 am – 8 pm

M

M

T

T

W

W

T

T

F

F

S

S

S

S

If C = (A in parallel with B) and (A and B are homogeneous):

If C = (A in parallel with B) and (A and B are heterogeneous):



accountability



measurement units








composed services




CONTRACTUAL DURATION AND MEASUREMENT PERIOD

Contractual duration Services are guaranteed in the

contractual duration. It means that the contractual duration of the composed service is constrained by the durations of the component services

Measurement period Each component service within

the SLA owns a specific measurement period.

The measurement period of the composed service is constrained by the corresponding component services.


Measurement period

MP of CS1

MP of CS2 …

MP of CSn

MEASUREMENT PERIOD

If the component services starts simultaneously, it is generally the least common multiple (l.c.m.) of each component’s measurement period

Otherwise initially the two measurements periods will be out of phase and need to be aligned



accountability



measurement units








composed services



TUAL ISSUES RELATED TO SERVICE COMPOSITION MANAGEMENT

MONITORING PLANS

It is necessary to develop and implement an appropriate monitoring plan, conducting representative sampling, and to report the results. map the relationships

between composing and composed services.


MONITORING PLANS

The monitoring plan must identify and provide information about each monitoring point. Each monitoring point must be located on the topology and labeled. The same points will identify monitoring points both for composing and composed

services.

Check point 1 Check point

2

Check point 3

CONTRACTUAL TERMS AND CONDITIONS

Context definition according to different

contexts, contract lifecycle can match different patterns and contract contents can vary (e.g., SaaS in Next Generation Networks, Cloud service contracts)

Domain definition As also drawn in the

perspectives of service contracts must be domain specific in order to better fit specific situations of a domain in real world practice. Such service contracts features are usually shared as reusable professional knowledge within a specific domain.

Since contracts are made up of subject, parties, terms and conditions, at least, it is necessary that even the composition of terms and conditions must be related.


CONCLUSIONS AND FUTURE WORKS

CONCLUSIONS AND FUTURE WORKS

Contribution: the paper explores how service composition, with specific focus on service levels, shapes technical, legal and organizational aspects related to the contract of the composed service and discusses the feasibility of the composition according to different aspects.

Conclusion: it is necessary to integrate aspects related to service levels design and management in contract management process in order to consider constraints and features related to service composition, which are fundamental in contract enactment and further enforcement. In this way issues like sustainability and feasibility of service contracts could be partly routed. An approach and tools encapsulating these topics could be very effective for several stakeholders involved in SLM and CM processes and could be useful for what if analysis, assessment for guaranteeing certain service level and sensitivity analysis.

Further works: development of: a methodology for the integration of technical, commercial, strategic and contractual

elements in SLA definition a platform supporting the composition of service levels, with attention to the constraints

they will create at contractual level.


Thank you!

Documents

Does service composition suffice to define business contracts for IT services in Networked organizations