Browsing by Author "Pienaar, W. J."
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- ItemDie beraming van verhoogde streeksinkome wat uit ekonomies geregverdigde padbouprojekte spruit(AOSIS OpenJournal, 2005) Pienaar, W. J.This article identifies the possible development benefits than can emanate from economically justified road construction projects. It shows how the once-off increase in regional income resulting from investment in road construction projects, and the recurring additional regional income resulting from the use of new or improved roads can be estimated. The difference is shown that exists between a cost-benefit analysis (to determine how economically justified a project is) and a regional economic income analysis (to estimate the general economic benefits that will be developed by investment in and usage of a road). Procedures are proposed through which the once-off and recurring increases in regional income can be estimated by using multiplier and accelerator analyses respectively. Finally guidelines are supplied on the appropriate usage of input variables in the calculation of the regional income multiplier.
- ItemEconomic aspects of pipeline transport: A South African perspective(AOSIS OpenJournals, 2009-06) Pienaar, W. J.Pipeline transport is unique among modes of transport in that the pipe, which facilitates freight movement, is both the way and the vehicle, and it is permanently connected to terminals, which facilitate freight storage. This feature makes it the only mode of transport that does not require any materials or goods handling. In view of the facts that pipeline infrastructure is extremely capital intensive and that it has an unprecedented longevity, pipeline transport enjoys the highest level of economies of scale of all modes of transport. This economy is subject to steady and enduring high levels of demand. It is also the only mode of freight transport of which the operations do not require a return journey, whereby joint cost due to empty running is avoided. The commercial transport of crude oil and petroleum products by pipeline and the envisaged new investment in this mode of transport are receiving increased attention in South Africa. Transnet Pipelines recently obtained permission from the National Energy Regulator of South Africa (Nersa) to construct and operate a new 60-cm petroleum products pipeline 704 kilometres in length from Durban to Gauteng. In addition, the newly-formed Petroline consortium recently obtained permission to construct and operate a 30 cm petroleum products pipeline 199 kilometres in length from Maputo to Nelspruit, with an extension of 249 kilometres in length eventually to Kendal, where it can be linked up with the present Transnet pipeline network. The disadvantages of pipeline transport lie mainly in its extreme functional speciali sation and dependence upon sustained high-volume traffi c. The initial cost of installation is high and justifi ed only when both the demand and supply are guaranteed to continue for an indefi nite period. Despite the fact that tank ships run empty during return trips, pipeline transport can only compete with sea transport between the same origin and destination if the pipeline route is considerably shorter than the sea route, or where sea transport is subject to exceptional charges, such as heavy canal dues. The economic assessment of a pipeline necessitates the investigation of several alternatives in order to determine whether the project is justifi able in terms of the economic resources its commercial existence will require. Firstly, alternative locations of the pipeline may have to be compared. A second consideration is the size of the pipeline, since one with a larger diameter, and capable of handling a greater traffi c volume, involves higher initial investment cost but lower costs for pumps and energy to propel the pumps. A third decision concerns the choice of pump technology. Most pumps are driven by electric motors, although diesel engines or gas turbines can also be used. A fourth important consideration is whether the refi nery should be located at the beginning of the line (upstream, close to the oil fi eld or the port of entry) or at the end of the line (downstream, close to the market). The fi fth step in the economic evaluation is to compare the pipeline cost with the cost of the next best transport alternative, which is usually rail transport. If these investigations indicate that a pipeline promises to be technically feasible, fi nancially viable and economically justifi ed, detailed design of the pipeline may commence. In terms of market participants the supply of pipeline transport is the most highly concentrated of all freight transport modes. With a few exceptions, there is but one crude oil, one products and one natural gas pipeline connecting producing areas or refi neries and areas of consumption. This high degree of monopoly results from declining unit costs with increases in capacity, so that the lowest costs are achieved by a concentration of output in a single pipeline. Therefore, pipeline operations that can fulfi l entire market demands are pure natural monopolies. Where the distance between supply points (such as geographically separated oil fi elds or ports of entry) is far in relation to the delivery distance to the market area, such an area’s fuel demand can often be most effi ciently fulfi lled by two or more different pipeline operations. The clients of a common carrier are direct competitors in the wholesale fuel market, therefore they should bear full cost responsibility for the service rendered by the pipeline. Service below total cost to a client implies that it is subsidized by its competitors. The only instance when delivery can take place below total cost is when: • the necessary spare capacity exists to accommodate the consignment (i.e. that the opportunity for another consignment to be delivered at full cost is not jeopardized); • all the avoidable (i.e. short-run) costs are covered and some contribution to unavoidable (i.e. fi xed or long-run) costs is made; and • the consignment delivery would not have taken place at a price covering full costs.
- ItemEstimation of increased regional income that emanates from economically justified road construction projects(AOSIS OpenJournals, 2005) Pienaar, W. J.This article identifies the possible development benefits than can emanate from economically justified road construction projects. It shows how the once-off increase in regional income resulting from investment in road construction projects, and the recurring additional regional income resulting from the use of new or improved roads can be estimated. The difference is shown that exists between a cost-benefit analysis (to determine how economically justified a project is) and a regional economic income analysis (to estimate the general economic benefits that will be developed by investment in and usage of a road). Procedures are proposed through which the once-off and recurring increases in regional income can be estimated by using multiplier and accelerator analyses respectively. Finally guidelines are supplied on the appropriate usage of input variables in the calculation of the regional income multiplier.
- ItemGuidelines for the choice of economic public infrastructure projects(AOSIS OpenJournals, 2002) Pienaar, W. J.This article provides guidelines for selecting public infrastructure projects based on economic criteria. Project evaluation, selection and prioritisation criteria are listed, followed by a description of the way in which the result of each evaluation technique should be interpreted. Criteria that should be adhered to in the selection of mutually exclusive projects and the prioritisation of functionally independent projects in order to maximise net social benefit in the long run are supplied. Application of the proposed investment decision rules is illustrated through the use of examples. Two techniques are proposed that can be used as additional decision-making instruments when evaluated projects show similar degrees of long-term economic viability.
- ItemLogistics aspects of petroleum pipeline operations(AOSIS, 2010) Pienaar, W. J.The paper identifies, assesses and describes the logistics aspects of the commercial operation of petroleum pipelines. The nature of petroleum-product supply chains, in which pipelines play a role, is outlined and the types of petroleum pipeline systems are described. An outline is presented of the nature of the logistics activities of petroleum pipeline operations. The reasons for the cost efficiency of petroleum pipeline operations are given. The relative modal service effectiveness of petroleum pipeline transport, based on the most pertinent service performance measures, is offered. The segments in the petroleum-products supply chain where pipelines can play an efficient and effective role are identified.
- ItemLogistics aspects of pipeline transport in the supply of petroleum products(AOSIS OpenJournals, 2008-06) Pienaar, W. J.The commercial transportation of crude oil and petroleum products by pipeline is receiving increased attention in South Africa. Transnet Pipeline Transport has recently obtained permission from the National Energy Regulator of South Africa (Nersa) to construct and operate a new petroleum products pipeline of 60 cm diameter from Durban to Gauteng. At an operating speed of 10 km/h the proposed 60 cm Transnet pipeline would be able to deliver 3,54 million litres of petroleum product per hour. This is equivalent to 89 deliveries per hour using road tank vehicles with an average carrying capacity of 40 000 litres of fuel per vehicle. This pipeline throughput is also equivalent to two trains departing per hour, each consisting of 42 petroleum tank wagons with an average carrying capacity of 42 500 litres of fuel per wagon. Considering that such road trucks and rail wagons return empty to the upstream refineries in Durban, it is clear that there is no tenable long-term alternative to pipeline transport: • pipeline transport is substantially cheaper than road and rail transport; • pipeline transport is much safer than rail and especially road transport; and • pipeline transport frees up alternative road and rail transport capacity. Pipeline transport is a non-containerised bulk mode of transport for the carriage of suitable liquids (for example, petroleum commodities, which include crude oil, refined fuel products and liquid petro-chemicals), gas, slurrified coal and certain water-suspended ores and minerals. In South Africa, petroleum products account for the majority of commercial pipeline traffic, followed by crude oil and natural gas. There are three basic types of petroleum pipeline transport systems: 1. Gathering pipeline systems 2. Crude oil trunk pipeline systems 3. Refined products pipeline systems Collectively, these systems provide a continuous link between extraction, processing, distribution, and wholesalers’ depots in areas of consumption. The following activities are involved in the flow of goods between place of origin and place of consumption or application: (1) Demand forecasting, (2) Facility site selection, (3) Procurement, (4) Materials handling, (5) Packaging, (6) Warehouse management, (7) Inventory management, (8) Order processing, (9) Logistics communications, (10) Transport, (11) Reverse logistics. Because cost is incurred without adding value each time goods are handled (activity 4) at a terminal or storage facility, a primary logistics objective is to eliminate handling wherever possible. With the carriage of crude oil and petroleum products by pipeline this objective is fully met. Commodity intake, haulage, and discharge are combined in one process, usually a remotecontrolled operation. Pipeline transport is a non-containerised bulk mode of transport thereby obviating the need for packaging (activity 5) and returning empty containers. Pipelines provide a direct and long-term link between these origins and destinations. If necessary a continuous service can be provided with no need for a return trip or a reverse pumping process (activity 11). The elimination of handling, packaging and reverse logistics activities contribute substantially to the high measure of economies of scale that pipeline transport enjoys. The article provides a description of each of the eleven logistics activities in the context of pipeline transport. Effective logistics service is a prerequisite to help ensure that customers receive the required products at the desired quality and quantity, where and when needed. The most pertinent determinants of logistics service performance are (1) suitability, (2) accessibility, (3) goods security, (4) transit time, (5) reliability and (6) flexibility. The article offers a discussion of the extent to which pipeline transport conforms to each of these measures of effectiveness.
- ItemLogistics management: its origin, conceptual evolution and meaning as a contemporary field of study(AOSIS OpenJournals, 2003) Pienaar, W. J.This article traces the origin of the word logistics, outlines its conceptual evolution, and explains the meaning thereof as a field of study in a contemporary management context. The contextual development of the concept is traced from its origin in Greek, along with its successive adoption in Late Latin, French and Dutch, up to its contemporary usage in Afrikaans. The article describes the establishment of the word logistique in French as a military concept during the Napoleonic wars, and its later extension to commercial usage subsequent to the Second World War. The development of the concept in a commercial context since then is detailed. Contemporary descriptions of logistics relating to its meaning in a commercial sense are discussed. Thereafter the article offers a contemporary definition of logistics in a business management context. It indicates how effective business logistics adds value. Finally the primary activities that form part of the logistics supply chain of products are briefly discussed.
- ItemLogistieke beplanning met behulp van simulasie modellering : 'n gevallestudie(Operations Research Society of South Africa (ORSSA), 2002) Loubser, J. S.; Visagie, S. E.; Pienaar, W. J.Hierdie artikel bied ’n uiteensetting van die gekombineerde gebruik van objek-georiënteerde programmering en simulasie, met die doel om ’n onderneming se logistieke funksies te ontleed en te beplan. Die huidige bedryfstelsel van ’n koerieronderneming se ontvangs- en verspreidingsaanleg word geëvalueer deur gebruik te maak van ’n objek-georiënteerde simulasie. Uit die simulasieresultate blyk dit dat daar ’n wanbalans in die kapasiteitsbelading van sommige werkstasies bestaan. Die onderneming se benutting van die meeste van sy hulpbronne is redelik goed, maar deur ’n herstrukturering van aktiwiteite is dit moontlik om ’n meer doeltreffende stelsel te verkry. Die model is die eerste rekenaarmatige voorstelling van die onderneming se aktiwiteite, en vul ’ n leemte in die beplanningsfunksie. Aangesien die model die verwagte resultate van aanpassings in die werkswyse en/of fisiese veranderinge aan die aanleg kan bereken, kan dit ook gebruik word vir strategiese besluite.
- ItemLogistieke bestuur : die oorsprong, konseptuele ontwikkeling en betekenis daarvan as ’n hedendaagse studiegebied(AOSIS OpenJournal, 2003) Pienaar, W. J.This article traces the origin of the word logistics, outlines its conceptual evolution, and explains the meaning thereof as a field of study in a contemporary management context. The contextual development of the concept is traced from its origin in Greek, along with its successive adoption in Late Latin, French and Dutch, up to its contemporary usage in Afrikaans. The article describes the establishment of the word logistique in French as a military concept during the Napoleonic wars, and its later extension to commercial usage subsequent to the Second World War. The development of the concept in a commercial context since then is detailed. Contemporary descriptions of logistics relating to its meaning in a commercial sense are discussed. Thereafter the article offers a contemporary definition of logistics in a business management context. It indicates how effective business logistics adds value. Finally the primary activities that form part of the logistics supply chain of products are briefly discussed.
- ItemThe mathematical basis of business logistics as a field of study(AOSIS OpenJournals, 2006-06) Pienaar, W. J.This article describes the meaning of the word logistics, outlines its mathematical basis and explains the meaning thereof as a contemporary field of study. The concept of logistics management is described in a business context and the strategic, tactical and operational tiers thereof are identified. The relationship that exists between systems analysis and logistics management is indicated. The role and essence of operations research in logistics decisionmaking are described. The most pertinent operations research topics in the field of logistics as well as the mathematical competencies a logistician should possess, are identified.
- ItemOperations Research : an indispensable toolkit for the logistician(Operations Research Society of South Africa, 2005) Pienaar, W. J.ENGLISH SUMMARY : This paper traces the origin of the word logistics, outlines its conceptual evolution, and explains its meaning in contemporary usage. The background that led to the introduction of Logistics Management and Operations Research (OR) as undergraduate fields of study at the University of Stellenbosch is sketched. The concept of Logistics Management is described and its strategic, tactical and operational tiers, as well as the different activities that form part of the logistics supply chain process are identified. The role and necessity of OR in decision-making within each activity and in the coordination between the various activities are outlined. OR techniques most pertinent to the field of logistics are identified and the analytical competencies that a logistician should possess are indicated.
- ItemPrinciples of social cost-benefit analysis of public road projects followed in South Africa(Southern African Institute for Industrial Engineering, 2018 -10 -12) Pienaar, W. J.ENGLISH ABSTRACT: This article discusses the most pertinent principles that underlie the preferred social cost-benefit analysis methodology to evaluate public road projects in South Africa. The ‘cost’ component of the analysis is the once-off investment cost sacrificed to establish a facility, and the ‘benefit’ component is the recurring reduction of disutility emanating from the operation, maintenance, and use of a facility. To determine future road-user benefits, the article develops a social surplus criterion that is termed ‘socio-economic user surplus’. A procedure is provided of the way that social cost-benefit analysis should be supplemented by the application of equity weighting, with a view to indicating both the expected allocative efficiency and distributive efficiency of a proposed road project. Lastly, the article discusses why the economic impacts that may stem from economically justified road projects are not considered in a social cost-benefit analysis.
- ItemA proposed regulatory framework for road and rail freight transport in South Africa(AOSIS OpenJournals, 2007-12) Pienaar, W. J.The increase in the number of freight vehicles on South Africa’s rural road network has received substantial attention. Insinuations persist that long-distance road freight haulage is of a somewhat unsavoury economic nature, and that strict economic re-regulation of the land freight transport is necessary. During the 1970s road transport replaced rail carriage as the dominant form of longdistance freight transport (excluding minerals and ore) in South Africa. On long hauls road freight carriers transport certain primary products of an organic nature (such as timber, fish and agricultural produce), some semi-finished goods, many finished goods and most consumer goods. Road freight carriers are continuously gaining market share on long-distance links where rail transport is the more cost efficient mode. The greater value added by road freight carriers in comparison with rail transport through service effectiveness is often more than the cost premium paid for utilising their service rather than making use of rail transport. Throughout history, governments have involved themselves in transport. A diverse range of arguments have been advanced for this involvement in transport, including the following: (1) Control of excessive competition, (2) co-ordination of transport, (3) integration of transport with economic policy, (4) maintenance of safety, security, and order, (5) provision of costly infrastructure, (6) provision of public goods, (7) recovery of the true resource cost of transport inputs, (8) regulation of harmful conduct and externalities, (9) restraint of monopoly power, and (10) social support. A set of nine instruments can be identified that governments apply to influence the performance of the freight transport industry: (1) Legislation, (2) direct supply, (3) fiscal measures, (4) monetary measures, (5) moral appeal and persuasion, (6) policies relating to strategic commodities, (7) procurement policy, (8) provision of information, and (9) research and development. The best prospects for a sound development of land freight transport activity in South Africa will be offered within the framework of a free-functioning freight transport market.
- ItemQuantifying freight transport volumes in developing regions : lessons learnt from South Africa's experience during the 20th century(Taylor & Francis, 2012-12) Havenga, Jan H.; Pienaar, W. J.A number of attempts were made during the 20th century to develop national freight flow information for South Africa. This paper discusses these contributions and attempts to identify the major reasons why the research did not give rise to long-term strategic infrastructure planning. It is important to learn these lessons to avoid making the same mistakes during the critical large-scale infrastructure investments that are unfolding in the first half of the 21st century. The paper starts with an overview of the development of South Africa’s surface freight transport infrastructure, and then provides a cross-country comparison of South Africa’s key freight indicators. This serves to underscore the importance of a long-term approach to such infrastructure investment.
- ItemSelection and scheduling of jobs with time-dependent duration(Operations Research Society of South Africa, 2007) Seegmuller, D. M.; Visagie, Stephan E.; De Kock, H. C.; Pienaar, W. J.ENGLISH SUMMARY : In this paper two mathematical programming models, both with multiple objective functions, are proposed to solve four related categories of job scheduling problems. All four of these categories have the property that the duration of the jobs is dependent on the time of implementation and in some cases the preceding job. Furthermore, some jobs (restricted to subsets of the total pool of jobs) can, to different extents, run in parallel. In addition, not all the jobs need necessarily be implemented during the given time period.