A literature review of vehicle routing problems (VRPs) in general, and specifically airline scheduling problems and the airline taxi problem, is provided. A real-world airline taxi scheduling problem is described as experienced by a tourist airline oper- ating in the Okavango Delta, Botswana. In this problem, a daily schedule is drawn up manually by a team of experienced schedulers a few days before the day in ques- tion. In this research, a slightly relaxed version of the problem is considered in order to develop heuristics and modelling methods which will be useful for general cases. Various methods and heuristics are proposed for the problem and tested on a small version of the problem as well as the full-sized version. The most promising methods are demonstrated and solutions provided. One of the methods was applied to the actual problem to demonstrate the practical usefulness. In this case a schedule with a cost 12% lower than the manual schedule cost was achieved. All the heuristics and methods are applicable to certain other VRPs, particularly real-world or highly- constrained VRPs. An example is provided of a solution method for a real-world instance of the multi-vehicle capacitated vehicle routing problem (MVCVRP). An- other example is provided of a standard, benchmark instance from the internet of a capacitated vehicle routing problem with time windows (CVRPTW).

No description available.

The problem was to review and evaluate operations research techniques and models that had been applied in the airline industry and to discover problem areas where further research is needed. The method was to review management and operations research literature pertaining to airlines, and to formulate the thesis outline on the basis of literature consulted. More specialized literature was then sought under each of the main chapter headings: Marketing, Production, Airports, Finance. In Marketing, little was found that originated from airline companies, except in the area of forecasting. Advertising and pricing models studied were chiefly from manufacturing industries. Airline Production, the revenue-earning part of airline operation, has been extensively studied by operations researchers in the airline industry. Reservations systems, manpower planning, scheduling of aircraft and crews and passenger check-in and baggage handling were main topics of study. Airport models dealing with traffic congestion, Air Traffic Control, aircraft, maintenance, and inventory control have been successfully implemented. Financial models have been developed largely by airframe manufacturers as selling tools for new aircraft, and for market research by the plane builders. Cash flow models and models that aid financial control have been applied. General conclusions are that operations research has been investigated as a means to better airline management in most departments of airline operation. Much remains to be done to develop practical operations research competence in the following areas: 1. Advertising and Pricing. 2. Routing and Scheduling of aircraft and crews. 3. Financial Investment. The volume of the literature on operations research is growing rapidly. This thesis includes only a small sampling of the work done prior to 1971. For more intensive study, bibliographies of current and past work should be consulted. An excellent source of bibliographical data is the International Abstracts in Operations Research, by the International Federation of Operational Research Societies, (IFORS). / Business, Sauder School of / Graduate

M.B.A. / This study is concerned with an investigation into the manual labour reporting system as currently operated by South African Airways (SAA) Technical. This was necessary, as a large percentage of the time sheet hours were not being captured with the net result being that costs and the resultant effects were becoming distorted. The primary purposes of this research was to identify the reasons for the current difficulties being experienced with labour cost recovery within SAA Technical in order to propose changes to rectify the impasse. The following reasons for the labour hour losses were identified: • Ineffective operational control methods. • Deployment of geographically dispersed data capturers. • Computer programming errors in the transfer routines. These problems naturally lead to a loss of control. The following improvements after rectification were noticeable: • In January 1997, average labour hour under recovery was as high as 46%. After rectification, losses were down to 15% (cf. 4.3). • The management accounting reporting document was greatly revised; thus rendering improved service to and understanding by the users. • The automated labour reporting bar scanning system currently being implemented would also benefit from the rectified computer transfer program. It may thus be concluded that the research was beneficial to SAA Technical operation and provided solid reasons for the labour hour losses. If the recommendations as presented further on in this study are adhered to, there should be no reason for the present situation not to maintain or improve the current improvements.

No description available.

M.Com. (Transport Economics) / In the past, air freight was generally a by-product of passenger orientated airlines in the sense that excess payload and unsold passenger seats were sold as air cargo space. In recent years, this trend has changed and it is observed that the air freight industry is increasingly becoming an industry in itself. The individual market share of scheduled international air freight operations within the air transport industry is currently approximately 35,8%. In South Africa, compared to the rest of the world, the historical development of air freight has been slower and confined primarily to the one national carrier (South African Airways (SAA)). The purpose of this study is, to firstly, determine the potential for growth in the air freight market within and outside South Africa. Secondly, to isolate and describe the factors within SAA which are sub-optimal and therefore have a negative impact on the development of the full potential of the air freight services of the carrier. The overall conclusion of the study is that the market for air freight within and outside of South Africa can be expanded significantly. This conclusion is dependent on the positioning and equipping of the freight division of SAA independently from passenger services, together with the provision of specialist knowledge and systems required for effective air freight management.

D.Com. (Business Management) / In this study the impact of the trend towards liberalisation of international air transport regulation was analysed. Through this analysis a strategic vision is then proposed for regulatory content in the management of international air transport. The movement to liberalise international air transport has necessitated a review of the international regulatory framework. This study focuses on a particular aspect of the regulatory framework namely regulatory content. Regulatory content is broken up into its constituent parts, which are discussed in relevant chapters ...

The use of expensive and highly specialized equipment in any industry is only advisable if the eost of the equipment can be justified by a sufficiently large output. The greater the output, the smaller will be the cost of the equipment to be borne by each unit. Thus, once such equipment has been purchased, management endeavours to maintain output at a maximum in order to reduce unit costs or to increase profits. It is for this reason that airline managements continually endeavour to increase the utilization of jet aircraft. By increasing the number of revenue flying hours only one hour each week on one jet aircraft, an airline will realize an additional net contribution to overhead (or profits) of approximately $60,000 per year. One method of increasing utilization is to decrease the downtime of the aircraft for maintenance purposes. This requires a reduction of the total elapsed time of the maintenance check. The critical path technique has found wide application in solving the general problem of reducing the time required to complete a project which consists of many inter-related jobs. For example, the technique has been used to reduce the time required for constructing a building, for completing the periodic overhaul of a chemical plant, and for completing the Polaris Missile Development Program. It was therefore felt that the critical path technique might be of use in solving this problem of increasing the utilization of jet aircraft. This thesis, based on the results of a study carried out at Canadian Pacific Air Lines during the months of May through August, 1963, describes the various ways in which the technique can be of use in solving this problem. It was found that the technique did have a wide applicability. In the initial period of application, it would be of great value as a tool for analyzing the problems of the check. It can be used both to point out the jobs or chains of jobs which prohibit the reduction of the check time and also to direct the revision of the scheduling of these jobs in such a way that the elapsed time is reduced. This reduction of elapsed time will have the effect of increasing the number of jobs which must be completed at the earliest possible time if the check completion time is to be a minimum. As a result there will be a greater need to use the technique both for scheduling and monitoring all the jobs of the check. / Business, Sauder School of / Graduate

published_or_final_version / Business Administration / Master / Master of Business Administration

Disruption Management in the airline industry plays an important role in airline operations. The goal of disruption management is to minimize the costs associated with disruptions while returning to the original schedule. Methodologies using advanced tabu search (TS) were investigated to solve two flight rescheduling problems: the aircraft grounding problem and the reduced station capacity problem. The objectives of both problems were to minimize the schedule recovery costs associated with flight schedule modifications and deviations from the original route, which are composed of the sum of delay costs, cancellation costs and aircraft route swap costs. Reflecting the cost of the deviation from the original route, the swap cost was modeled as a non-linear function of the swaps of aircraft between routes. In each problem, a stand-alone tabu search approach was constructed to holistically minimize the sum of the cost of delays, cancellations and swaps. Next a hybrid method which combined a time-space network flow model with side constraints and a limited tabu search was created which attacked the problem in two steps: first, the total cost of delays and cancellations was minimized by the network flow model; second, a limited tabu search was conducted to minimize the number of swaps. A second hybrid method was then developed, which utilized the result from the first hybrid method as starting solution for the stand-alone tabu search. The results of the experiments performed with the hybrid methods clearly indicate that integrating TS with classical optimization methods has marked potential for improving the results of a disruption management technique.