Integrating IVHM and asset design

Integrated Vehicle Health Management (IVHM) describes a set of capabilities that enable effective and efficient maintenance and operation of the target vehicle. It accounts for the collecting of data, conducting analysis, and supporting the decision-making process for sustainment and operation. The design of IVHM systems endeavours to account for all causes of failure in a disciplined, systems engineering, manner. With industry striving to reduce through-life cost, IVHM is a powerful tool to give forewarning of impending failure and hence control over the outcome. Benefits have been realised from this approach across a number of different sectors but, hindering our ability to realise further benefit from this maturing technology, is the fact that IVHM is still treated as added on to the design of the asset, rather than being a sub-system in its own right, fully integrated with the asset design. The elevation and integration of IVHM in this way will enable architectures to be chosen that accommodate health ready sub-systems from the supply chain and design trade-offs to be made, to name but two major benefits. Barriers to IVHM being integrated with the asset design are examined in this paper. The paper presents progress in overcoming them, and suggests potential solutions for those that remain. It addresses the IVHM system design from a systems engineering perspective and the integration with the asset design will be described within an industrial design process

Selecting a suitable system architecture for testing and integration

A system architecture is selected in the early design phases of a product. A trade-off is made between the most important architectural views during this selection process. The required system functionality is realized in an architecture which is maintainable, extendible, manufacturable, testable and integratable. This work investigates how an architecture can be selected, such that it is testable and integratable. The elements of an architecture which is suitable for testing and integration are introduced first. These elements are: components, interfaces between components and a layering. The division of the system into components determines how the system can be integrated and how many integration steps are required. Next to that, not all components need to be selected for system level integration and testing. Some, low-risk, components are integrated and tested on a lower level or not tested at all. The selection of components to be considered for integration and testing also influences which interfaces are considered. The selection of an interface infrastructure influences integration and testing, next to the interfaces which result from component and interface selection. The interface infrastructure can reduce or increase the number of interfaces in the system. An interface infrastructure could also introduce that specific connectors need to be developed resulting in additional risk and more required testing. And finally, a layering defines how the system, consisting of components and interfaces, is clustered. This layering reduces the complexity of the system and therefore the complexity of the integration and test plan. The layering for integration and testing can be defined fairly late in the development process just before integration and testing begins. Next to that, the layering for integration and testing can be different than the normal organizational or functional layerings of a system. More layerings can be defined and used next to each other. Guidelines and examples of suitable selections of components, interface infrastructure and layerings will be given in the presentation

Simulation modelling software approaches to manufacturing problems

Increased competition in many industries has resulted in a greater emphasis on developing and using advanced manufacturing systems to improve productivity and reduce costs. The complexity and dynamic behaviour of such systems, make simulation modelling one of the most popular methods to facilitate the design and assess operating strategies of these systems. The growing need for the use of simulation is reflected by a growth in the number of simulation languages and data-driven simulators in the software market. This thesis investigates which characteristics typical manufacturing simulators possess, and how the user requirements can be better fulfilled. For the purpose of software evaluation, a case study has been carried out on a real manufacturing system. Several simulation models of an automated system for electrostatic powder coating have been developed using different simulators. In addition to the evaluation of these simulators, a comprehensive evaluation framework has been developed to facilitate selection of simulation software for modelling manufacturing systems. Different hierarchies of evaluation criteria have been established for different software purposes. In particular, the criteria that have to be satisfied for users in education differ from those for users in industry. A survey has also been conducted involving a number of users of software for manufacturing simulation. The purpose of the survey was to investigate users' opinions about simulation software, and the features that they desire to be incorporated in simulation software. A methodology for simulation software selection is also derived. It consists of guidelines related to the actions to be taken and factors to be considered during the evaluation and selection of simulation software. On the basis of all the findings, proposals on how manufacturing simulators can be improved are made, both for use in education and in industry. These software improvements should result in a reduction in the amount of time and effort needed for simulation model development, and therefore make simulation more beneficial

Retention and application of Skylab experiences to future programs

The problems encountered and special techniques and procedures developed on the Skylab program are described along with the experiences and practical benefits obtained for dissemination and use on future programs. Three major topics are discussed: electrical problems, mechanical problems, and special techniques. Special techniques and procedures are identified that were either developed or refined during the Skylab program. These techniques and procedures came from all manufacturing and test phases of the Skylab program and include both flight and GSE items from component level to sophisticated spaceflight systems