Project schedule optimisation utilising genetic algorithms

This thesis extends the body of research into the application of Genetic Algorithms to the Project Scheduling Problem (PSP). A thorough literature review is conducted in this area as well as in the application of other similar meta-heuristics. The review extends previous similar reviews to include PSP utilizing the Design Structure Matrix (DSM), as well as incorporating recent developments. There is a need within industry for optimisation algorithms that can assist in the identification of optimal schedules when presented with a network that can present a number of possible alternatives. The optimisation requirement may be subtle only performing slight resource levelling or more profound by selecting an optimal mode of execution for a number of activities or evaluating a number of alternative strategies. This research proposes a unique, efficient algorithm using adaptation based on the fitness improvement over successive generations. The algorithm is tested initially using a MATLAB based implementation to solve instances of the travelling salesman problem (TSP). The algorithm is then further developed both within MATLAB and Microsoft Project Visual Basic to optimise both known versions of the Resource Constrained Project Scheduling Problems as well as investigating newly defined variants of the problem class.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Neural network based simulation of sea-state sequences

The present PhD study, in its first part, uses artificial neural networks (ANNs), an optimization technique called simulated annealing, and statistics to simulate the significant wave height (Hs) and mean zero-up-crossing period ( ) of 3-hourly sea-states of a location in the North East Pacific using a proposed distribution called hepta-parameter spline distribution for the conditional distribution of Hs or given some inputs. Two different seven- network sets of ANNs for the simulation and prediction of Hs and were trained using 20-year observed Hs’s and ’s. The preceding Hs’s and ’s were the most important inputs given to the networks, but the starting day of the simulated period was also necessary. However, the code replaced the day with the corresponding time and the season. The networks were trained by a simulated annealing algorithm and the outputs of the two sets of networks were used for calculating the parameters of the probability density function (pdf) of the proposed hepta-parameter distribution. After the calculation of the seven parameters of the pdf from the network outputs, the Hs and of the future sea-state is predicted by generating random numbers from the corresponding pdf. In another part of the thesis, vertical piles have been studied with the goal of identifying the range of sea-states suitable for the safe pile driving operation. Pile configuration including the non-linear foundation and the gap between the pile and the pile sleeve shims were modeled using the finite elements analysis facilities within ABAQUS. Dynamic analyses of the system for a sea-state characterized by Hs and and modeled as a combination of several wave components were performed. A table of safe and unsafe sea-states was generated by repeating the analysis for various sea-states. If the prediction for a particular sea-state is repeated N times of which n times prove to be safe, then it could be said that the predicted sea-state is safe with the probability of 100(n/N)%. The last part of the thesis deals with the Hs return values. The return value is a widely used measure of wave extremes having an important role in determining the design wave used in the design of maritime structures. In this part, Hs return value was calculated demonstrating another application of the above simulation of future 3-hourly Hs’s. The maxima method for calculating return values was applied in such a way that avoids the conventional need for unrealistic assumptions. The significant wave height return value has also been calculated using the convolution concept from a model presented by Anderson et al. (2001).EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Modeling and analyzing a health care supply chain system

A Thesis presented on Improving and Redefining the Supply Chain in Healthcare, defining existing problems with current Supply Chain applications, and reviewing current applications and trends in the Supply Chain culture within the Manufacturing Industries and Healthcare Industries. Research of successful applications of new, and improvements to existing supply chain methodologies are presented. The concept of a future Supply Chain Management System, extending the boundaries of conventional Healthcare Supply Chain to include both conventional customer (Healthcare Materiel and Capital Assets Requestors and Distributors) and the nonconventional (the Healthcare Beneficiary), is presented in detail. Final discussions and conclusions of this concept are offered as a review of this concept for the reader of this manuscript.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

The Narrative Frame of Daniel: A Literary Assessment

This paper presents a fuzzy multicriteria group decision making approach for evaluating and selecting information systems projects. The inherent subjectiveness and imprecision of the evaluation process is modeled by using linguistic terms characterized by triangular fuzzy numbers. A new algorithm based on the concept of the degree of dominance is developed to avoid the complex and unreliable process of comparing fuzzy numbers usually required in fuzzy multicriteria decision making. A multicriteria decision support system is proposed to facilitate the evaluation and selection process. An information systems project selection problem is presented to demonstrate the effectiveness of the approach

Activity-based cost estimation in a push/pull advanced manufacturing system

WOS: 000188762400005The objective of this paper is to estimate the manufacturing and product costs by using activity-based costing (ABC) method in an advanced manufacturing system that is run under either material requirements planning (MRP) or just in time (JIT) system. ABC is a method that can overcome many of the limitations of traditional costing systems. This paper reports and discusses the implementation of the ABC alongside a mathematical and simulation model to estimate the manufacturing and product cost in an automated manufacturing system. The potential effects of manufacturing planning and control strategies implemented on financial structure of the manufacturing system are initially analysed. ABC has been used to model the manufacturing and product costs. An extensive analysis has been carried out to calculate the product costs under the two strategies. The comparison of the two strategies in terms of effects on the manufacturing and product costs are carried out to highlight the difference between the two strategies. (C) 2003 Elsevier Science B.V. All rights reserved

Recycling of cutting tools in flexible manufacturing systems

WOS: 000184143800004Flexible manufacturing systems (FMS) are complex, with a high variety of entities. In particular, tool management is critically important for timely manufacture. Since a large number of tools flow in a medium-size FMS, it is important to design and operate the tool management system (TMS) to guarantee unmanned and streamlined manufacturing. In this work, a new strategy is developed to minimize the tooling cost by recycling the partially used tools within the manufacturing cell. particular TMS design strategy, entitled workpiece-oriented tool flow, is considered. Under this strategy, three different tool issue sub-strategies are used to assign tools to available machines. These sub-strategies are measured against cell and tooling performance criteria and are compared to each other with and without recycling. Conclusions are drawn for some different cell configurations and the results are highlighted for different performance criteria