Save Your Sprint! How to Avoid the Three Types of Bad Project Estimates


cloud of obscurity; and they create rigid, unreliable schedules.


Why Tools Matter


So why is this such a big deal? Because rigid schedules are inherently anti-Agile. One reason Agile methodologies favor “individuals and interactions” over “processes and tools” is that traditional project management tools are too inflexible for Agile’s dynamic, collaborative approach. Unfortunately, too many Agile teams are unwittingly using tools that work against them by locking them into bad estimates and rigid schedules. Or, if they reject tools altogether, they are left without much of a schedule at all (and a white board that looks like this):

Figure 1: A typical Agile whiteboard shows the difficulty of analog time tracking

But a new generation of project management tools is emerging that allow teams to estimate their time in ranges rather than single points. Here’s how it works:


Use Estimates that Reflect the Way You Actually Work.


Give your time estimates in ranges of real time (i.e., 4-7 hours). Not only is this the way you really think about time and work, it has a buffer of uncertainty built right in for everyone to see. It sounds simple, but the impact is profound. With a ranged estimate you are giving a best-case (low end) and worst-case (high end) scenario of how long it will take you to complete the task. This range captures and conveys uncertainty; an estimate with a wide range, such as 2-5 days, conveys more uncertainty than a narrower estimate, such as 1-2 hours. As work progresses, the uncertainty narrows, and the schedule becomes an even more accurate reflection of reality.

Figure 2: A ranged estimate and its corresponding probability curve

Benefits of Using Ranged Estimates

  • Let you plan accurately even within a large range of uncertainty
  • Allow teams to drive uncertainty out of the schedule early (since it can be seen clearly)
  • Prevent sandbagging; and
  • Create a neutral, honest point of communication within teams and with business owners


Agile represents a move to more interactive, humanistic software development methods. While reliance on processes and tools is downplayed in favor of communication and collaboration, the demands placed on Agile teams requires more and better planning, estimation, and organization— not less. As such, Agile teams benefit from tools that appropriately support and enhance the way they work.


About the Author

Jason Carlson is the co-founder of LiquidPlanner, online project management software built on an innovative probabilistic scheduling system using Agile methodologies (20 sprints and counting!). Email him your questions at [email protected].


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