Track train dynamics analysis and test program: Methodology development for the derailment safety analysis of six-axle locomotives

The operational safety of six axle locomotives is analyzed. A locomotive model with corresponding data on suspension characteristics, a method of track defect characterization, and a method of characterizing operational safety are used. A user oriented software package was developed as part of the methodology and was used to study the effect (on operational safety) of various locomotive parameters and operational conditions such as speed, tractive effort, and track curvature. The operational safety of three different locomotive designs was investigated

Operational Excellence in Manufacturing, Service and the Oil & Gas: the Sectorial Definitional Constructs and Risk Management Implication

The current global business climate has not been favorable to most firms irrespective of industry affiliation. That condition necessitated companies to adopt operational excellence as a strategy for optimising output with little resources, reducing lead time with the efficient use of assets and employees and avoiding safety and health issues to people and the environment. As a result of the need for operational excellence, many kinds of literature defined the concept based on the context of industry or sector. Industries such as manufacturing, services, oil and gas, mining and so many industries to mention a few, have their unique construct in the definition and therefore causing dilemma on which dimension to hold on to. It is against this backdrop that this paper synthesizes and integrate all the varying dimensions and fuses out similarities, differences and the antecedence of research directions taken on the few mentioned sectors. The paper thus concludes that the unique construct among all the definitions is continuous improvement, cost reduction, quality, time utilization, operational efficiency, staff involvement and output optimisation. However, they varied on risk management, staff health, safety and the concern for the environment, which is unique to oil and gas industry and that can affect the choice of research variables

Some conservative stopping rules for the operational testing of safety-critical software

Operational testing, which aims to generate sequences of test cases with the same statistical properties as those that would be experienced in real operational use, can be used to obtain quantitative measures of the reliability of software. In the case of safety critical software it is common to demand that all known faults are removed. This means that if there is a failure during the operational testing, the offending fault must be identified and removed. Thus an operational test for safety critical software takes the form of a specified number of test cases (or a specified period of working) that must be executed failure-free. This paper addresses the problem of specifying the numbers of test cases (or time periods) required for a test, when the previous test has terminated as a result of a failure. It has been proposed that, after the obligatory fix of the offending fault, the software should be treated as if it were completely novel, and be required to pass exactly the same test as originally specified. The reasoning here claims to be conservative, inasmuch as no credit is given for any previous failure-free operation prior to the failure that terminated the test. We show that, in fact, this is not a conservative approach in all cases, and propose instead some new Bayesian stopping rules. We show that the degree of conservatism in stopping rules depends upon the precise way in which the reliability requirement is expressed. We define a particular form of conservatism that seems desirable on intuitive grounds, and show that the stopping rules that exhibit this conservatism are also precisely the ones that seem preferable on other grounds

Air Traffic Management Safety Challenges

The primary goal of the Air Traffic Management (ATM) system is to control accident risk. ATM safety has improved over the decades for many reasons, from better equipment to additional safety defences. But ATM safety targets, improving on current performance, are now extremely demanding. Safety analysts and aviation decision-makers have to make safety assessments based on statistically incomplete evidence. If future risks cannot be estimated with precision, then how is safety to be assured with traffic growth and operational/technical changes? What are the design implications for the USA’s ‘Next Generation Air Transportation System’ (NextGen) and Europe’s Single European Sky ATM Research Programme (SESAR)? ATM accident precursors arise from (eg) pilot/controller workload, miscommunication, and lack of upto- date information. Can these accident precursors confidently be ‘designed out’ by (eg) better system knowledge across ATM participants, automatic safety checks, and machine rather than voice communication? Future potentially hazardous situations could be as ‘messy’ in system terms as the Überlingen mid-air collision. Are ATM safety regulation policies fit for purpose: is it more and more difficult to innovate, to introduce new technologies and novel operational concepts? Must regulators be more active, eg more inspections and monitoring of real operational and organisational practices

Airport safety, capacity and investment

Paper presented at SurTech 2002, The Aviation Surveillance Technologies ConferenceThe title ‘Airport Safety, Capacity and Investment’ could potentially cover an enormous range of topics and approaches. Techniques used include probabilistic risk analysis, queueing theory, operational research, and cost benefit analysis (CBA). The aim here is both to give an impression of the whole subject and to focus on a few key topics. Surveillance technology plays an important part in delivering safety and capacity, but has to be seen in the larger system picture, particularly when investment is contemplated

Spacelab program requirements, level 1

The design and development of Spacelab is reported including the ground support equipment, facilities, and operational planning. The shuttle interface, and user requirements are discussed along with product assurance and safety

Space station crew safety alternatives study, volume 1

The first 15 years of accumulated space station concepts for initial operational capability (IOC) during the early 1990's were considered. Twenty-five threats to the space station are identified and selected threats addressed as impacting safety criteria, escape and rescue, and human factors safety concerns. Of the 25 threats identified, eight are discussed including strategy options for threat control: fire, biological or toxic contamination, injury/illness, explosion, loss of pressurization, radiation, meteoroid penetration and debris

Sodium Sulfur Technology Program Nastec

The NaSTEC program focuses on developing currently available sodium sulfur cells for use in space applications and investigating the operational parameters of the cells. The specific goals of the program are to determine the operational parameters and verify safety limits of Na/S technology battery cells; test long term zero-g operation; and create a life test database. The program approach and ground and flight test objectives are described in textual and graphic form