What Does Airline Capacity Have To Do With Lean?

Observation on Lack of Capacity

A recent article in the Wall Street Journal (The Reason Southwest Stopped Overbooking), which contained excerpts from an interview with Southwest Airlines’ CEO Gary Kelly, brought out the need to address airline capacity issues on the ground and in the air. Responding to a question on the impact of lack of infrastructure improvements, Gary made the following comment.

“In the air, it makes their trips longer and longer. A flight today from New York to Dallas is significantly longer for scheduled flight times than it was 20 years ago, and that’s true for city pairs across the U.S. When we experience these longer flight times, we change the schedule so that they’re no longer “delayed” according to the schedule, but now all you’ve done is you’ve built in the delay time into the schedule, and I just fear that as time goes by over the next generation that there’s a limit to how much you can simply increase the flight times before you just reach gridlock.”

Lean Product Development

One of the concepts of lean is that capacity constraints slow all work flowing through the system[i], [ii]. In product development, you see projects taking longer because key resources are overloaded. Therefore, the resources multitask causing the project work to take longer. Because the project work takes longer, the estimates for the next project incorporate those delays, making the next project even longer. You create a self-reinforcing cycle causing project durations to keep growing.

Reinforcing cycle leading to ever growing task durations

Recommendations

Lean product development provides methods to keep your projects moving as quickly as possible and avoid the expansion cycle, including the following.

• Load resources to no more than 70% capacity with planned work (all forms of project work). Product development work is inherently variable. That unassigned capacity enables the schedule to absorb unknowns about the project that will show up. In addition, it enables your schedule to reflect time needed by people to attend meetings or training. For comparison, factories, which have low task variability, plan for less than 100% capacity utilization to enable flexibility for unexpected changes in order sizes and for equipment maintenance and updates.
• Work on the highest priority[iii] available task as quickly as possible, while minimizing interruptions and multitasking. Work efficiency and the ability to complete something drops significantly with interruptions and multitasking. Since you have the work broken down into small pieces (see the next bullet), it is much easier to stay focused and ask people to wait a little while so you can finish.
• Break down the near term tasks into 1-3 day durations. Using fine granularity helps provide focus on the work that needs to be completed. You can quickly identify roadblocks and take steps to resolve the issues and get back on track.
• When collecting updates, focus on the work that still needs to be done and the activities needed to complete the work. Using team updates to review what was (or wasn’t) done, can make team members defensive and often prevents team members from focusing on future work.

Closing Thoughts

Airlines have seen flight times increase in response to capacity issues. As companies try to schedule resources to 100% capacity, project durations also rise. Changing the way you manage the work can drive significant improvements in schedule durations and help prevent the reinforcing cycle from growing in your organization

[i] From The Principles of Product Development Flow, by Donald G. Reinertsen, Celeritas Publishing, 2009.

[ii] From Mastering Lean Product Development: A Practical, Event-Driven Process for Maximizing Speed, Profits, and Quality, by Ronald Mascitelli, Quality Books, Inc, 2011.

[iii] Tasks on the critical path or critical chain should have the highest priority.