The Tetrad-Tradeoff Principle
The Tetrad-Tradeoff Principle is a broadening of the Success and Commitment principles. Tetrad-Tradeoff
is a project management term also known and referred to in a slightly different aspect as the
Triple Constraint, the Holy Trinity or the Iron Triangle. Some people equate the Triple Constraint
to a three-legged stool (cost, time, quality) that will tip over if one leg is shortened without
compensating for the imbalance. Others liken the Tetrad-Tradeoff Principle to a four-cornered,
flexible frame where one corner is fixed and another can be moved but not without impacting
the other two.
Triple or Tetra, either way what it means is that the project's variables, product scope,
time-to-produce, cost-to-complete and quality grade are interconnected and cannot change without
a corresponding, balancing change on one or more other variables. The variables are measures
of efficiency. Agreements must be reached within the project organization on the balance between
them. Should a cost-to-complete constraint be imposed on the team, then either one or all of
the other variables must be adjusted. Without agreement to the balance there cannot be a reasonable
commitment to achieving the project's goals.
Once agreement is reached and something occurs during the project that jeopardizes the balance,
the organization collectively has to re-define and commit to a new balance. Oftentimes something
does happen that jeopardizes the original goals. Maybe the competition is launching a similar
product soon so the window of opportunity must be accelerated. Maybe new technology is more
complex than anticipated. Ultimately, success criteria and measurements of efficiency should
be reviewed and validated throughout the life of the project. In the face of a changing environment,
just maintaining the original objectives will likely result in disappointment at the end of
It's easier to comprehend the connection between the project variables when put in the context
of the hockey world. Each team sets schedule, budget, and quality (wins and/or game performance)
objectives at the beginning of each season. As an example, assume the schedule includes a Stanley
Cup series appearance, the budget is $60,000,000 and the quality is a minimum of 50 wins. A
team losing a key player mid-season could see its quality of play suffer resulting in less wins.
Less wins could lead to missing the playoffs. More money could be spent bringing in an adequate
replacement player for the injured one.
In another example, a season shortened by a labor disruption would most likely result in
less revenue for the owners. In January 2003, the NHL's Ottawa Senators and Buffalo Sabres faced
poorer on-ice performance resulting from each team's bankruptcy filings.
When an event occurs during the course of business that puts goal realization at risk, goals
must be adjusted. Without adjusting goals there will be undue pressure by the team, its owners
and its fans, to achieve the original goals. There will likely be disappointment at the end
of the season.
7. Yorio, Kara. What does bankruptcy
mean for fans? The Sporting News, 16 January 2003, Retrieved 17 January 2003, from http://www.sportingnews.com/voices/kara_yorio/20030116.html