“…Underestimation of the required time and budget (also known as over-optimism) is considered to be one of the main factors associated with project failure (Harvey Nash & KPMG, 2017;KPMG, 2017;PricewaterhouseCoopers, 2014;Project Management Institute, 2018). Over-optimistic estimates have been linked to overruns in projects (Buehler et al, 2010;Flyvbjerg et al, 2002;Kutsch et al, 2011;Lang et al, 2013;Nelson & Morris, 2014), scope overload (Bjarnason et al, 2010(Bjarnason et al, , 2012Buschmann, 2009;Shmueli et al, 2016a) and over-requirements (Buschmann, 2010;Coman & Ronen, 2010;Shmueli et al, 2015Shmueli et al, , 2016aShmueli et al, , 2016b. In addition, organisations focused on cost savings may underestimate costs or select projects in which costs have been underestimated (Connolly & Dean, 1997).…”