Too Optimistic in Time Planning?

"One of the most infamously delayed and expensive infrastructure projects in U.S. history is the Boston Big Dig (Central Artery/Tunnel Project), which was originally planned to be completed in 1998. It ended up being completed at the end of 2007, about 9 years late. Accompanying the delay were massive financial costs, rising from the initial estimated cost of $2.8 billion to a final cost of over $8 billion, or nearly $22 billion when factoring in interest and related projects."

"Many factors may contribute to the overoptimistic estimation of task completion times. One is that people typically focus on positive future outcomes when planning their time. As a result, they disregard past experience of similar tasks that ran over schedule. Instead, they believe that "this time will be different." Motivational factors also play a role. Due to self-serving bias, people often blame external or unstable causes (e.g., the task being too difficult) for their failures to meet deadlines while overlooking their own"

People frequently underestimate the time required to finish tasks, a cognitive bias called the planning fallacy. Underplanning causes missed deadlines, personal stress, and substantial cost overruns on large public projects. The Boston Big Dig exemplifies such overruns, finishing nine years late and costing many billions more than initially estimated. Causes include focusing on optimistic future outcomes while disregarding past experiences, and motivational biases like self-serving attributions that shift blame away from personal responsibility. Time estimation improves when plans are anchored in prior task histories and when potential social consequences and accountability are considered.

Read at Psychology Today