OVERVIEW

OUTLINE OF DISSERTATION PROJECT


Modeling Queuing Networks for Decision Making and System's Performance Analysis using the PDQ library


1 Introduction

1.1 Aims and objectives

* The aim of this project is to provide a general tool with a GUI, which helps the user to define models of closed queuing networks using simple graphical "drag and drop" elements and then solve the defined problem using the PDQ library, which is a free open source software. The solution should be represented in a graphical way as well (plot diagrams, color use, etc).
* To investigate the possibly different existing approaches in designing an interface for representing closed queuing network problems, then analyze the alternatives, and finally select one of these approaches or propose a new approach, explaining the rationale and the reasons of choosing this design approach (potential benefits, advantages and disadvantages of the selected approach).


1.2 Queuing Theory

1.2.1 Definition

* Queuing Theory is the mathematical study of waiting lines (or queues), and it is generally considered a branch of operations research because the outcomes of the theory are applicable to make business decisions about the resources needed to provide service.

1.2.2 Problems with Queues

* Properties of queues and queue problems
* Common Algorithms (like FIFO LIFO, etc) and their properties
* Applications of queuing theory in everyday life and in cybernetics (PSTN example)

1.2.3 Queuing Networks
* Open Queuing Networks and Closed Queuing Networks
* Queuing Networks and Markov Chains
* Mathematical Background and Algorithms.
Queuing systems use Markov Chains which model the system in each state. Incoming traffic is modeled via a Poisson distribution and is a subject to Erlang's queuing theory assumptions.

1.3 Performance Analysis and Decision Making (introduction to the problem)
* Performance Analysis Techniques
* Systems' Modeling and Performance Evaluation
* Existing tools in the area of decision making based on queuing networks modeling (PDQ library)
* Which approach do these tools follow in matters of design


2 Literature Review/Survey/Requirements

2.1 Previous work on queuing networks and available software

2.2 Theories and applications (tools) related to queuing problems and decision making

2.3 How this approach differs from, or extends previous work in this area


3 Modeling of Closed Queuing Networks using the PDQ software

3.1 Description of the library characteristics, capabilities and functions

3.2 How this software can be used to help in modeling and solving closed queuing networks

3.3 Designing the GUI (analyzing properties, aims, requirements, alternatives, implementation and evaluation issues)

3.4 Implementation
* Programming language(s)
* Additional software that has been used (APIs)


4 Results

4.1 In which way the user defines the problem (queuing network model) using the features of the program

4.2 Which is the range of problems that this program finally solves?
* Large queuing networks and how they can be modeled and solved using the program.

4.3 Demonstration of how the program solves these problems and how the solution(results) is presented to the final user
* Graphical representation of the model
* Plots and Tables of the results
* Demonstration of the solution using colors

5 Conclusions

5.2 Evaluation of the final program in matters of effectiveness, usability, performance and design
* How close to reality is the proposed from the program solution
* How fast this solution is calculated from the program
* Compatibility and extensibility
* Drawbacks and bottlenecks

5.3 Comparison of the developed program with previous implementations that model and solve queuing networks

* Advantages and Disadvantages of the selected design and implementation approach

5.4 In which extend the achievements meet the requirements? Discussion

* Initial objectives and how they have been achieved or not
* What is the contribution in the area of queuing networks that has been made by this piece of work

5.5 Future work

* How the developed tool could be extended
* What should be done by anyone who would like to continue this project