Iron Triangle Kills in Boston…

boston skyline

… Skyline Unharmed

Short-sighted demands on software teams usually don’t kill people. Software development is often described with a construction analogy. The Big Dig construction project was under exactly that kind of pressure. On July 10th, 12 tons of tunnel ceiling collapsed and killed a motorist. On July 20th, Mitt Romney ordered the tunnel to be closed. Let the finger pointing begin.


The Big Dig is a multi-year construction project to fix very expensive traffic problems in downtown Boston. The Massachusetts Turnpike Authority has a good background article. Traffic congestion was projected to cost $500 million per year to motorists by 2010 without making changes. Project costs – $14.6 billion (more than 30 year payback period) versus an initial estimate of $2.5 billion.


The 6-lane overpass was to be replaced with 8 to 10 lanes of tunnels underneath the city, protecting the skyline of Boston from large concrete structures. Unlike the “protect the view” argument of previous New Orleans adminstrators against a hurricane barrier, there are practical arguments to building tunnels. The MTA was never proposing to “do nothing.”

Project Timeline

According to this Associated Press article, the Turnpike Commission found no problems that “rose to the level of a public safety threat.”

Timothy Johnson, author, project manager, and owner of Delta Project Solutions, speculates in his article that the source of poor quality may have been pressure on the engineering/construction teams to work faster.

It doesn’t take a lot of effort to find stories of the governor’s office pressuring the project to move faster. There was political capital on the line. So… the project moved faster. Quality shortcuts were inevitably taken. And now Mitt Romney wants to know where the blame lies. Am I missing something on the cause-and-effect graph?

Corrobarating Evidence

The US Transportation Department released a scathing audit this week, charging Big Dig officials with misleading federal officials on Feb. 1 that the project would cost $10.8 billion, and divulging later the same day that it could cost an additional $1.4 billion.

“It stands as one of the most flagrant breaches of the integrity of the federal-state partnership in the history of the nearly 85-year-old federal-aid highway program,” the audit said.

Gov. Paul Cellucci (R) fired the head of the Big Dig, James Kerasiotes, just minutes after meeting with federal highway officials. But that does not solve the larger issue of how to complete projects of this magnitude on schedule and on budget.

Christian Science Monitor, April 2000

From the same article:

The Big Dig, he points out, is the worst example of cost overrun [Ernest Frankel, a professor emeritus at MIT’s school of engineering]’s ever seen. He and his colleagues warned Massachusetts officials that the project could not be done for the state’s initial estimate of $2.5 billion. Which raises a larger point: While government officials often claim – rightly – that added time and costs are necessary on big projects, critics say authorities too often low-ball construction schedules and estimates to gain funding and public support.

Why Quality Suffers

When project constraints put the squeeze on, there are four ways we can respond. The common expression of the Iron Triangle is that a project can be represented as a triangle with three legs – cost, time, scope. If you put pressure on the project without increasing one of the legs of the triangle, then quality suffers. In this project, it looks like the consequences of pressure were mortal.

  1. Sacrifice quality to increase functionality
  2. Increase cost to increase functionality
  3. Increase time to increase functionality
  4. Delay some functionality to deliver other functionality

How To Use Timeboxes For Scheduling Software Delivery

Apparently, the folks on the big dig were pressured to choose option #1, which is not a good idea. They also apparently made liberal use of options 2, 3, and 4. Perhaps there were competence problems, or process problems, but regardless, politics trumps people the same way that people trump process.


Don’t sacrifice quality to meet some arbitrary metrics. Without accounting for sunk costs, review the project from its current state to its projected end state. If the additional time and costs will still allow the project to meet the ROI targets, then keep working. If not, cancel the project. If you go with option 1, bad things can happen.

5 thoughts on “Iron Triangle Kills in Boston…

  1. Great builds on my original comments, Scott. Your analysis from the CSM caps it off nicely. Now we just get to sit back and watch the drama of finger-pointing unfold. I think Governor Romney can kiss his presidential aspirations good-bye.

  2. hi it a pleasure for me so read the article on big dig project but there are a few things i will like to know the first is who where the stakeholders of this project,what were the business case use in this project and how was it prepared and by whom also what was stated as the benefits and lastly what was the main risk involveand what decision were reached and how were the managed.thanks for the understanding am looking forward to get the reply.

  3. i would like to know who where the stakeholders of this project,what was the business case in this project and how was it planned? thanks for understanding. i am looking forward to the reply.

  4. Johnson and kay,

    Thanks very much for the comments and questions. Unfortunately, I’m one of the many people who slowed down to watch the train wreck that is the big dig.

    Without doing additional research, I couldn’t identify the stakeholders other than to say “the taxpayers” – which, I believe, are both Mass. and federal tax payers. Not sure what the value-prop for someone who owns an dry cleaner in Midland, TX would be.

    The business case seems to be “Boston motorists save $500 millon per year”, which made sense relative to the initial cost estimates – but not the actual costs.

    If y’all do additional research on the dig, let us know what you find. Thanks!

Leave a Reply to Scott Sehlhorst Cancel reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.