No abstract

Management located in Mamonal facilities; in order to know the percentage of idle times in performed productive processes and to identify the main triggers, through the estimation of the proportion of time played in specifics activities in a certain period of time, using instantaneous observations of work areas and employing probability sampling to generalize the findings. El presente artículo está orientado a la implementación de la técnica del muestreo de trabajo en la Corporación de Ciencia y Tecnología para el desarrollo de la Industria Naval, Marítima y Fluvial-COTECMAR, más específicamente en el Departamento de Producción de la Gerencia de Mantenimiento y Reparación de Buques en la Planta; con el fin de conocer el porcentaje de tiempos ociosos en los procesos productivos ejecutados e identificar las principales causas que lo genera, a través de la estimación de la proporción de tiempo dedicado a actividades específicas durante cierto periodo de tiempo, empleando para ello la toma de observaciones instantáneas de las áreas de trabajo y utilizando el muestreo probabilístico para generalizar los resultados del estudio. Abstract Resumen

Hull coating (external blasting and painting) renewal (repair) is a part of routine ship maintenance. It is carried out only when the ship is in a dock (graving dock, floating dock, or slipway). For a regular maintenance schedule, the scope of hull coating repairing works dictates the duration of stay of a ship in the dock. It is very vital therefore to estimate the scope of work for hull coating before docking. As soon as the ship is docked, a joint hull inspection by representatives of the owner, drydock, and coatings supplier accurately determines the hull coatings scope of work. Most of the time, the inspection result does not match with the preplanned dock operation schedule. Hence, the overall dock operation schedule gets affected due to delay or early undocking of a ship. Hull coating repair and related information for 149 cargo ships were collected from a single shipyard. It was analyzed and presented in both tabular and graphical forms to show the relationship between the scope of work and the age, size, and type of ships. The physical size of a ship has a great influence on the hull blasting and painting repairing works irrespective of design parameters and types of the ship. Using ship dimensions, actual surface area, and other factors, a method of estimating the hull coating scope is proposed. In this article, the authors have made an attempt to identify the independent variables that influence the scope of work (dependent variable), and suggested the possible interrelationships between the dependent and independent variables, which appeared to be linear.

The Dynamic Positioning (DP) System is a complex system with significant levels of integration between many sub-systems to perform diverse control functions. The extent of information managed by each sub-system is enormous. The complex level of integration between sub-systems creates more possible failure scenarios. A systematic analysis of all failure scenarios is tedious and for an operator to handle any such catastrophic situation is breath taking. There are many accidents where a failure in a DP system has resulted in fatalities and environmental pollution. Therefore, reliability assessment of a DP system is critical for safe and efficient operation of marine and offshore vessels. Traditionally, the reliability of a DP system is assessed during the design stage by methodologies such as Failure Mode Effects and Analysis (FMEA), Proving Trials, Hardware In-the Loop (HIL) testing, Site-Specific Risk Analysis, DP capability Analysis and during operation by annual trials to verify functionality. All these methods are time consuming, involving a lot of human effort and notably no analysis of previous accidents are indicated in the reliability assessment. This imposes in-built uncertainty and risk in DP system during operation. In this paper, a new concept of Dynamic Positioning Reliability Index (DP-RI) is introduced and a state-of-the-art advisory decision making tool is proposed. This tool is developed based on information from various sources including Offshore Reliability Data (OREDA), International Marine Contractors Association (IMCA) Accident database, DP vendor equipment failure databases, DP System supplier’s manuals, previous system level FMEA and HIL testing results, Site specific risk analysis documents, Project design specification and Operator’s operational experiences. Thus, DP-RI addresses the pitfalls of existing reliability assessment methods and will be an efficient tool in reducing the number of DP-related accidents.