Abstract
Weather downtime (WDT) is a logistical and financial risk when planning operations or offering services. Such risk is typically identified and managed in advance using statistical predictions based on historical weather data. Estimates of programme and cost for offshore construction work may vary, not because of the nature of a task, or the environment at the location, or the capability and price of a vessel, but because estimates of WDT have been calculated in different ways.
Estimates of WDT are required in order to develop a realistic programme for complex and long duration projects. Therefore, a good understanding of the analytical options and a feel for the implications of the many and varied approaches is key to finding optimal solutions regarding WDT assessments.
In this paper we consider a number of variants to the two principal approaches (namely ‘Weather Windows’ and ‘Simulation Based’ WDT analysis) to the derivation of WDT statistics. WDT estimates calculated using the same environmental input data, but alternative approaches are presented. The presentation highlights the potential variation in downtime statistics that can result from the alternative analyses, aiming to improve awareness of the application of such statistics when estimating project programme and cost at the planning stages.
