[Long Running Transactions Within Enterprise Resource Planning ERP System]

by

ACKNOWLEDGEMENT

I would take this opportunity to thank my research supervisor, family and friends for their support and guidance without which this research would not have been possible.

DECLARATION

I, [type your full first names and surname here], declare that the contents of this dissertation/thesis represent my own unaided work, and that the dissertation/thesis has not previously been submitted for academic examination towards any qualification. Furthermore, it represents my own opinions and not necessarily those of the University.

Signed __________________ Date _________________



TABLE OF CONTENTS

ACKNOWLEDGEMENTII

DECLARATIONIII

CHAPTER 3: METHODOLOGY1

Long Transactions1

2.2. Multiple versions of database state5

PP/T concurrency control mechanism7

Capabilities of a software agent9

Types of software agents10

Applications of software agents11

Simulation12

The coordination agent13

The data collection agent14

The interface agent15

An illustration of the proposed MAERP system15

The setting15

The example16

Phase I18

Phase II18

Phase III18

Research Methods19

Concurrency: Object-Oriented Programming and Programming by Contract28

Dependency Relations33

Concurrent Object-Oriented Programming and Program Lavering35

Intra-Object Contract, Inter-Object Contract, and TEAMWORK Assertion37

Parallel Program Design41

An Example for Concurrent Program Construction43

Determining: Shared Objects43

CHAPTER 4: RESULTS AND DISCUSSION45

Discussion45

Overview of the four cases51

The ManA case51

The ManB case52

The ManC case52

The ManD case53

How and why managerial agency influenced business benefits53

Web application server architecture54

User load structure55

TPC-W application56

Motivation57

CHAPTER 5: FORMALIZATION60

REFERENCES66

CHAPTER 3: METHODOLOGY

Researchers involved in agent research have used a variety of terms and offered definitions, explicating their use of each term. Although there is no general agreement as to what constitutes an agent, Franklin and Graesser (1996) provide taxonomy of autonomous agents and establishes how they are different from a computer program. In the literature, the term software agent is also referring to as “agent,” “autonomous agent,” intelligent agent,” and “business agent.” An agent is anything that can be viewed as perceiving its environment through sensors and acting upon that environment through effectors (Rusell and Norvig, 1995: p. 33). The term “agent” is used to represent software-based computer programs that have two abilities: (i) the ability for autonomous execution and (ii) the ability to perform domain oriented reasoning. In general terms, a software agent is an autonomous, goal-oriented, software-based computer program that operates asynchronously, communicating and coordinating with other agents as needed (Fox et al., 2000).

Long Transactions

Much research work has been done on long duration transactions. One of the most influential long duration transaction models is the saga model[2] proposed by Garcia-Molina. The basic idea of this model is to decompose each long duration transaction into a set of sub-transactions that can be executed separately. Each sub-transaction is a traditional transaction. Compensating transactions are used when the long duration transaction needs to be rolled back. Under the saga model, when it is necessary to roll back a long duration transaction, not only should the executed sub-transactions be compensated, but also all other transactions that either directly or indirectly used the intermediate results of the long duration transaction must be compensated[3]. Since the set of transactions that used the intermediate results of a long duration transaction cannot be predicted in advance, the compensating transactions can hardly be developed beforehand, and the compensation process must rely on human participation in most ...