An industry study published by the Independent Project Analysis group in 2012 reported that 78% of upstream projects in 2011 faced either cost or schedule overruns (Merrow, 2012). A similar report, published by EY in 2014, found 64% of projects faced cost overruns and 73% of projects faced schedule overruns (EY, 2014). Similarly, in 2017, the UK Oil & Gas Authority (OGA) published a study of lessons learned from UKCS oil & gas projects between 2011-2016, which reported "since 2011 fewer than 25% of oil and gas projects have been delivered on time with projects averaging 10 months' delay and coming in around 35% over budget." (OGA, 2017) This level of cost and schedule underperformance was not sustainable in the high oil price economic environment and is inconceivable in the lower oil price environment in which we now operate. We cannot continue to make the same mistakes, the need to learn is no more critical than in the deepwater arena: Wood McKenzie report the cost of developing a deepwater project has fallen by more than 50% since 2013 (Offshore, 2018), the increased investment in deepwater is likely to drive an upturn in cyclical costs meaning developments become increasingly marginal and unable to sustain overruns or delays and remain economic.