Most of the maintenance actions in the construction sector are still reactive and sporadic, based on subjective criteria. Usually, maintenance actions are performed when the building already presents unacceptable degradation levels, and the reactive maintenance actions carried out only correct the anomalies observed, not dealing with the causes, thus leading to additional costs and risks for owners. This study establishes a condition-based maintenance model applied to natural stone claddings. This model has a stochastic nature, in order to deal with the complexity of the degradation phenomena. For that purpose, Petri nets are used, providing an efficient tool to model the deterioration process and the maintenance decisions considered for stone claddings. The maintenance model is a full life-cycle model that encompasses: (i) the stochastic assessment of the degradation condition of the stone claddings, and their expected service life; (ii) and the inspections, maintenance and renewal processes. In this study, three maintenance strategies are considered: (i) major intervention only; (ii) combination of minor and major interventions; and (iii) combination of cleaning operations, minor and major interventions. The impact of the different maintenance strategies in the future performance and remaining service life of stone claddings is analysed, also evaluating the economic impact of each maintenance plan.
Abstract
Most of the maintenance actions in the construction sector are still reactive and sporadic, based on subjective criteria. Usually, maintenance actions are performed when the building already presents unacceptable degradation levels, and the reactive maintenance actions carried [...]
The design of safety critical systems calls for advanced software engineering models, methods and tools in order to guarantee safety requirements that can put human life at stake. When the safety critical system encompasses a substantial interactive component, the same level of confidence is required towards the human computer interface. Conventional empirical or semi-formal techniques, although very fruitful, do not provide sufficient insight on the reliability of the human system cooperation, and offer no easy way, for example, to quantitatively compare two design options. The aim of this paper is to present a method with related too1& and techniques for engineering the design and development of usable user interfaces for safety-critical applications. The specific application area which we will consider is air traffic control but most of the results will be valid for any application areas with similar requirements. Document type: Part of book or chapter of book
Abstract
The design of safety critical systems calls for advanced software engineering models, methods and tools in order to guarantee safety requirements that can put human life at stake. When the safety critical system encompasses a substantial interactive component, the same level of [...]
Condition-Based Maintenance Models for Stone Claddings 