You’ve probably heard the warning that “failing to plan is planning to fail.” Coined by Benjamin Franklin, the founding father of time management, that phrase might seem like prudent wisdom, but it’s impractical advice for 21st-century association executives.

Of course, planning is important in any organization, but the common impulse is to plan for best-case outcomes, ignoring the high likelihood that things can and will go wrong. A better adage is “failing to plan for problems is planning to fail.” This requires you to imagine and plan for contingencies and to build your capacity to react quickly when a plan goes off the rails—particularly when a costly project runs over budget and past deadlines.

When was the last time you saw a major project suffer from cost overruns? A 2014 study [PDF] of large IT projects found that only 16 percent succeeded in meeting the original budget. Those that didn’t suffered an average cost overrun of 189 percent.

Moreover, cost overruns often spiral out of control, resulting in even bigger disasters. Let’s say you draw money from a cybersecurity budget to cover unexpected expenses elsewhere. As a result, you’ve left yourself exposed to hackers, who might target and steal member data, resulting in a loss of member trust as well as bad PR.

The Planning Fallacy

Cost overruns largely stem from the “planning fallacy,” our intuitive belief that everything will go according to plan. The planning fallacy is one of many dangerous mental blind spots that scholars in cognitive neuroscience and behavioral economics call cognitive biases. Fortunately, recent research in these fields shows how you can use pragmatic strategies to address these judgment errors in your professional life.

Planning is important in any organization, but the common impulse is to plan for best-case outcomes, ignoring the high likelihood that things can and will go wrong.

For example, you can address the planning fallacy by planning around it. This involves anticipating what problems might come up and addressing them by using the research-based technique of prospective hindsight, in which you envision yourself in the future and look back at potential challenges in the present. Besides this broad approach, three specific techniques are effective for addressing the planning fallacy.

Look back at performance. First, use your experience with similar projects to inform your estimates for future projects. One healthcare association’s IT department had a systemic struggle with underestimating project costs. In one example, a database implementation project that was estimated to cost $2 million ended up costing $3 million and took four months longer than anticipated. Those in charge of projects should use past project costs to inform future projections. When the healthcare association did this, they made much more accurate project cost and timing estimates.

Break down a project into components. An insurance association struggled with a pattern of cost overruns in its event planning. Whey they looked at specific parts of the event, the biggest unanticipated money drain came from last-minute changes that staff were making to accommodate requests by members.

For instance, to accommodate young members, the association decided shortly before its annual conference to use a conference app. However, the short timeline resulted in high costs to set up the app in time for the event. To avoid similar problems in the future, the staff changed their event-planning process to engage members much earlier and committed not to make last-minute adjustments for stakeholders who had already had their say.

Get an external perspective. It’s always wise to ask for advice from people outside your bubble who have undertaken a project that’s similar to yours, especially if it’s new to you. Their experience can help you anticipate contingencies you may not have considered.

Remember that the key to addressing cost overruns is to remember that “failing to plan for problems is planning to fail.” Use this phrase as your guide, and you’ll avoid falling prey to the planning fallacy.