Thesis Presentation
Contributions in Distributed
Systems Engineering
by “Jari Koistinen”
Presenter : S. J. Paheerathan
Agenda
• Thesis Introduced
• Research Argument
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Claims
Evidence
Warrants
Qualification
Research Questions
Research Results
Author’s Contribution
Thesis Structure
Thesis Introduced
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Title:
Author:
Type:
Year:
Pages:
Parts:
Chapters:
Contributions in Distributed Systems Engineering
Jari Koistinen
Lit. & PhD
1998
412
V
17
Elements of Research Argument
Warrant
Claim
Evidence
Qualifications
•
•
•
•
Claim
Evidence
Warrant
Qualifications
Claims, Warrants, Evidences and
Qualifications
Two elements that must
be stated explicitly
• Claim
Warrant
Claim
Evidence
– What you want readers
to believe.
(You should be checked by
your doctor)
Qualifications
• Evidence
– Reasons they should
believe it.
(Your blood sugar reading is
200)
Claims, Warrants, Evidences and
Qualifications
• Warrants
Warrant
Claim
Evidence
Qualifications
– General principle, an
assumption or premise that
bridges the claim and its
supporting evidence
connecting them into a logically
related pair.
– Answers questions not about
whether the evidence is
accurate, but about whether it
is relevant to the claim or it can
be inferred from the evidence
(Whenever someone has a blood sugar
reading of more than 120 that’s a good
sign that she may have diabetes)
Claims, Warrants, Evidences and
Qualifications
• Qualification
Warrant
Claim
Evidence
Qualifications
– Limits the certainty of
conclusions
– Stipulate the conditions in
which the claim holds
– Address the readers
potential objections
– Make the author to
appear a judicious,
cautious, thoughtful writer
Your reading is 200evidence, so you should be checked,claim because that much
glucose in the blood is a goodqualification sign that you mayqualification have
diabetics, warrant unless, of course, you just ate something sugary.qualification
Claims, Warrants, Evidences and
Qualifications
Warrant
Claim
Evidence
One of the two elements
that must be stated
explicitly
• Claim
– What you want readers
to believe.
Qualifications
(You should be checked by
your doctor)
Properties of Claims
• They become the heart of the research/report and fully
reflects the personal contribution of the author.
– Are they capable of attracting the readers and meet their
expectations? (Are they substantive?)
– Will these lead the readers to think?, (Are they contestable?)
• Is this something they have long thought? OR
• Is it something they never thought about at all?
– Are they specific/explicit?
• Is it stated in language that is specific?
• Do the readers know what concepts to expect?
Claim of the Thesis
• Main Claim
Improvements are required to the state-of-the-art of
distributed object systems engineering to better meet
increasing business and product development
requirements.
Subordinate Claims
The technologies and computing platforms used to
support enterprise systems development must have at
least the following characteristics
1. Architecture and implementation techniques must enable rapid
evolution.
2. Systems must satisfy Quality of Service requirements such as
reliability, security and performance requirements.
4. Architecture and implementation must enable extension and
improvement at low cost by providing means for reuse.
5. Systems must have means for ensuring architectural and design
integrity as systems evolve for many years.
Claims, Warrants, Evidences and
Qualifications
Warrant
Claim
Evidence
One of the two elements
that must be stated
explicitly
• Evidence
– Reasons they should
believe it.
Qualifications
(Your blood sugar reading is
200)
Properties of Evidence
• Though the claim is the heart of a thesis, most of the
thesis will be devoted to supporting the evidence
–
–
–
–
–
Do the evidences certain or reliable? (Are they accurate?)
Do the qualifiers set within appropriate limit? (Are they precise?)
Are they sufficient?
Are they representative?
Are they authoritative?
• Applicable to the time/current
– Are they perspicuous?
• Can readers see the evidence as evidence?
Evidence
• Even recent proposals on high level structuring of object oriented
systems lack characteristics that make them suitable for
distributed object systems engineering. Classes are too finegrained for cost effective development and reuse of large
distributed systems.
• The development of large scale distributed object systems is
more difficult than in necessary as common object oriented
software engineering methodologies do not support separately
defined and managed interfaces.
• Methodologies today do not support the formal description of
design invariants, and it is difficult to maintain them during long
time of system evolution, they too do not support automatic
enforcement of architectural and design constraints.
Evidence (Cont..)
• QoS aspects such as reliability, security and
performance are hard to capture and take under
consideration with commonly used software
engineering techniques and methodologies.
– Explicit techniques are commonly used only for critical
systems such as flight control, patient monitoring and often
limited in dimensions and inadequate.
Claims, Warrants, Evidences and
Qualifications
• Warrants
Warrant
Claim
Evidence
Qualifications
– General principle, an
assumption or premise that
bridges the claim and its
supporting evidence
connecting them into a logically
related pair.
– Answers questions not about
whether the evidence is
accurate, but about whether it
is relevant to the claim or it can
be inferred from the evidence
(Whenever someone has a blood sugar
reading of more than 120 that’s a good
sign that she may have diabetes)
Properties of Warrants
• They are the basis of our belief and reasoning.
–
–
–
–
False warrants
Unclear warrants
Inappropriate warrants
Inapplicable warrants
Warrants
• Distributed computing is the infrastructure on which
present and future enterprises will built their information
systems.
– enterprises are increasingly becoming global, considering the
whole world as their market place.
– different parts of the business are widely distributed and they
need to share business critical information and functions
– failures or inadequacies in infrastructure will be very costly.
• To flourish enterprise must have functionally complete,
flexible and reliable information systems.
• Rapid deployment of new functions and incorporation of
new sites are critical for businesses today.
• Need to accommodate rapid change, search for new
ways of doing business, technologies.
Claims, Warrants, Evidences and
Qualifications
• Qualification
Warrant
Claim
Evidence
Qualifications
– Limits the certainty of
conclusions
– Stipulate the conditions in
which the claim holds
– Address the readers
potential objections
– Make the author to
appear a judicious,
cautious, thoughtful writer
Your reading is 200evidence, so you should be checked,claim because that much
glucose in the blood is a goodqualification sign that you mayqualification have
diabetics, warrant unless, of course, you just ate something sugary.qualification
Qualifications
• Development of large scale distributed
enterprise systems using object orientation.
Research Questions
• Is it possible to develop concepts and well-defined
language for coarse-grained modularization of object
oriented software such that we obtain multi-class
components that have well defined interfaces and
dependencies?
• Is it possible to introduce separately defined first class
interfaces such that systems are more evolve-able
and can be naturally mapped to distributed object
infrastructures without imposing any conceptual
burdens on developers?
– Whether separating inheritance and non-inheritance
boundaries, annotating interfaces with architectural
categories, and aggregating sets of tightly-knit interfaces
improve the internal quality of a software system?
Research Questions (Contd..)
• Is it possible to formalise architectural and design
constraints in a manner that is intuitive to use,
expressive enough and enables the implementation of
efficient checking procedures?
• Is it possible to introduce a specification technique
that enable us to describe, for distributed objects,
quality of service requirements and characteristics
involving multiple QoS requirements and
characteristics involving multiple QoS dimensions?
– If so, will it possible to use this technique both during the
design of multi-class components and as a run-time
representation for QoS information?
Research Results
• Concepts, language and tools for modularization and
structuring of multi-class components and interfaces
of large object oriented systems.
– Concepts have been implemented in a prototype tool and a
variation of concepts have been integrated with an industrial
design language and tool environment.
– Concepts have been applied to the design of a real
telecommunication application and resulted in more welldefined architectures and high-level structures.
Research Results (Contd..)
• Concepts, language and tools for the description and
enforcement of architectural styles for a variety of
architectural building blocks such as mutli-class
components, interfaces and individual classes.
– Concepts and language have been given a formal semantics
based on tree logic. Integration of a tree logic inference
engine within an industrial design environment has been
prototyped.
– User evaluation proved that commonly used design
constraints can be expressed in the language and that the
formal basis enables efficient implementation of real-time
checking.
Research Results (Contd..)
• Concepts, language and tools for the description and
exchange of QoS information for object oriented
components.
– The language has been implemented and a corresponding
run-time representation and wire representation has been
defined and implemented. It has been used to design a QoS
negotiation mechanism indicating adequate expressiveness.
– Concepts and language have been used in case studies with
good results.
Contributions of the thesis
• Efficient large-grained structuring of modules and
interfaces.
– Novel and improved concepts and a language for the
description and structuring of large grained modules and
interfaces.
• A refined interface concept separating different types of
interfaces and grouping of closely related interfaces
• case studies and practical experience indicate that systems can
be built with these concepts to be more easily evolved, enabling
iterative and parallel development, and mapped to distributed
object technologies.
• The concept and language enables the treatment of interfaces
as a first class concept in system architectures.
Contributions of the thesis (Contd..)
• Formal Architectural styles.
– Novel concepts and a language for the formal description of
invariants for architectural designs and design constraints.
• Allows general design languages to be used to develop systems
with specific architectural constraints and characteristics.
• Allows formal treatment and efficient checking while providing
adequate expressive power.
Contributions of the thesis (Contd..)
• QoS specification language and run-time
representations.
– Novel concepts for QoS specification of object oriented
components which are separate from any syntactic and
semantic descriptions of components.
• The language balances the expressibility with the need for
conformance checking of independent specifications of a
particular interface.
• A well defined language to enable independent implementation
of infrastructure components that can interchange QoS
specifications.
Structure of the thesis
• Collection of licentiate thesis, four conference papers
and two research reports.
– Part I - Summarises the research area, research questions
and results
– Part II - Licentiate Thesis, proposes concepts for dealing with
programming in the large and a case study on a real large
scale distributed system development
– Part III -Two papers,
• one is on the industrial application of the concepts presented in
the Lit. thesis and
• other is on further development, formalisation and
implementation of the architectural style concepts mentioned in
the Lit. Thesis.
Structure of the thesis (Contd..)
– Part IV - Papers and research reports on declarative QoS
specification on Object Oriented components.
– Part V - Epilogue, Concluding remarks.
– Bibliography
Thank You for your patience