Showing papers on "Service level published in 1974"

Level-of-service concept for evaluating public transport

Abstract: A system of evaluating service variables common to all public transport modes is proposed so that an existing system may be managed or improved and a new system may be built on the basis of its ability to fulfill a desired level of service. The variables discussed are those directly perceived by the user regardless of mode: overall trip speed and en route delay and comfort factors associated with the vehicle including density, acceleration, jerk, temperature, air flow, and noise. Improving one or more of these measurable variables bears an associated cost and design requirement. Since better service is desirable in certain situations while average service is sufficient in others, levels of service A through F are adopted for each variable. In the proposed system, level of service is determined by the use of a weighted average of rankings assigned to individual factors. Within tolerable limits, 40 percent of the overall ranking should be based on speed and delay and 60 percent on comfort factors. When an individual comfort variable becomes intolerable, the entire ride is at service level F. Application of the procedure results in reasonable comparisons of both systems and individual trips within a system.

Managerial inventory formulations with stockout objectives and fiscal constraints

Abstract: Most inventory formulations seek to minimize the sum of ordering costs, holding costs, and stockout costs: however, management often directs inventory policy by specifying a maximum investment level and/or a purchasing budget constraint. Within these limitations, they expect lower level managers to optimize some level of customer satisfaction, such as minimum stockouts or minimum shortages. The author has developed several cases of these “managerial” inventory formulations and has presented some computational results.

The Full Costs of Urban Transport. Part I: Economic Efficiency in Bus Operations; Preliminary Intermodal Cost Comparison and Policy Implications

Abstract: The downward spiral frequently experienced by transit companies when they increase fares to make up for declining demand is well known. It is characteristic of an increasing-returns-to-scale industry where consumer inputs are essential to the production process. This paper formally incorporates both agency and consumer inputs in a cost framework and explores the short- and long-run costs of bus services. In so doing it is possible to trade off both consumer and agency costs, to arrive at optimal service levels. It is these service levels, with the mode performing at its best, that form the basis of cost comparisons between transportation alternatives. We find that off-peak frequencies should be considerably shorter than those typically prevailing on bus transit systems, and that marginal cost pricing would require a zero fare in the off-peak and a fare of up to 20 cents in the peak. This suggests that current rates might be continued in the peak and abolished in the off-peak. A subsidy to maintain this scheme would be about 10% of the average cost of service when operation is in long-run equilibrium (optimized). In the realm of cost comparisons between alternative modes, options based upon the car are found to be among the cheapest for trips to the CBD except in the peak. In terms of public modes, dial-a-ride systems seem to have some economic justification for low density neighborhoods as a feeder to linehaul buses operating on freeways, but at high densities integrated bus service appears to be far more viable. The latter is markedly cheaper than a feeder bus + rapid rail alternative. Finally, there seems to be little economic justification for the current interest in non-standard buses for transit service.

An approach to warehouse design: matching the concept to the throughput

Abstract: Warehousing is a waste of time and money. Goods that are in store are idle goods and the longer they stay in storage the more they cost. The less warehousing, then, the better. A few companies have managed to organise a retailing operation without own warehousing by direct scheduling from manufacturer or supplier to the retail outlet. However, for the vast majority a warehouse is necessary in order to provide a buffer between supply and demand, to take advantage of bulk purchasing and to guarantee a service level to the customer on a reasonable number of products. Clearly, a warehouse should be scientifically sited and designed. It is at the hub of a distribution network and as such must be a highly efficient unit if it is not to wreck the entire system. In previous articles (RDM Jan/Feb and May/June 1974), the authors considered the overall distribution network including the determination of the number of warehouses and their siting. They now consider warehouse design and, more particularly, how this design should be matched to the throughput.

The Concept and Cost Elements of Physical Distribution

Abstract: The fundamental aim of any distribution system must be to provide the necessary levels of customer service, so as to maintain and expand profitable business, at the minimum total cost compatible with such service levels. All other objectives, in any distribution organisation, should directly or indirectly contribute towards achieving this basic aim.

Planning the ideal distribution network

Abstract: Which factors need to be examined in planning the most suitable, flexible and cheapest distribution network? Certain elements can be juggled with in working towards the solution: the type of transport, frequency of delivery, service levels — even the numbers and locations of supply points. In this article, Geoffrey Butcher emphasises the importance of the overall approach, whether for auditing a system here and now or planning for the 1990's. In future articles he will discuss transport and warehouse design.

The choice of service level

Abstract: The problem of what level of service to provide to customers is frequently a source of argument between marketing and distribution personnel This article examines the factors that can affect the range of choices and, with particular reference to a practical example, describes a method of determining the costs implied by changing the service level

Traveler preference for fare alternatives as a transportation planning input

Abstract: This paper deals with the effect of fare policy and transit service plans on mode-choice behavior. These issues were studied in the context of coordinating a new rail rapid transit service in San Francisco with the existing surface bus system in order to maximize the overall service level. To aid the process of simulating the effects of various bus and rail service plans and joint fare structures under study, a disaggregate model of sub-modal-choice behavior was developed. The model was calibrated with data collected in a field survey of bus patrons. These data were used to estimate the relative influence of fare level and time savings on sub-modal-choice behavior and to forecast the probable extent of rail rapid transit usage by current bus riders. Although the specific questions posed in this study were geographically unique, the underlying technical and policy issues could be applied to other similar situations involving the introduction of a new transportation service or facility.