Thursday, July 31, 2008

The Triple Constraint

The Triple Constraint or Project Management Triangle

A few weeks back when I was in Amsterdam for some training, I was reminded that I wanted to write about the Triple Constraint. What is the Triple Constraint you ask? Put basically, it is a term that is often used in Project Management to describe the tradeoffs that have to be made between scope, time, and cost within projects. While this is very important to running projects it is also one of life’s key principles as well.

The Triple Constraint is often times called the Project Management Triangle. In the picture above you’ll see a triangle formed between scope, cost, and schedule with quality being in the middle of the triangle. Scope is what you plan to do or deliver. Cost is often viewed as the effort needed to do whatever it is that you’re doing, this can be monetary (dollars, euros, and so on) and can also be the resources used to deliver what you’re doing. Schedule and time are often used interchangeably; this is how long it will take you to do what you’re planning to do. The reason that they form a triangle is that it isn’t possible to change one of these items without adjusting the other two. This is often where projects fail. You can certainly do a task faster (time or schedule) but you might have to hire someone else to help you do it (more money and effort) or you can deliver less (you might adjust what it is that you’re going to deliver), and in the middle of the triangle is the quality of what you’re delivering, so maybe what you’re doing doesn’t need to have the highest quality but it is certainly effected by scope, time, and cost.

When you think about it, most everything that you do in life is affected by the Triple Constraint. You have to make a trade off between all of these things. A while back I saw a picture about service that you could receive at a motorcycle shop, that said that you could receive three types of service good, cheap, fast, and that you could pick any two, this is another way of stating the Triple Constraint that is easily understood…

If you have good service fast it won’t be cheap

If you have good service cheap it won’t be fast

If cheap service fast it won’t be good

Projects are often failing because they don’t properly adjust when there are changes to any of these things. Projects’ scope often grows (they take on more work or what is being delivered expands) but then the cost (effort) and/or schedule (time) are not properly adjusted. Using effort and cost interchangeably can confuse some people but just realize that there is a cost that goes along with additional effort (maybe hiring additional people to do more work). If you’re costs have gone up from taking on more work and not adjusting the time needed to deliver that work, and not adjusting other work being delivered; this means that if you don’t increase your prices (to correspond with your additional resource costs), your revenue and profits might not be sufficient to stay in business. Another thing that often happens is that, if you don’t bring on more resources, your resources are now pulled from other work, so that other work now takes longer to deliver (time or schedule), which delays that work.

I have not mentioned skill and efficiency to this point. If something is being done by more experienced resources, they probably cost more (hourly rates, salary, and etc.) than less experienced resources, this is part of your cost (effort). While your more experienced resources tend to cost more because they’re more likely to know what needs to be done and how to do it, they can complete the work quicker than the less experienced resources, which means that it takes less time to do the work and they might be able to do other tasks. Having more experienced resources does not guarantee that they’re efficient or that they have good work habits. Skill and efficiency should not be overlooked.

If you look around in your everyday life, you’d be amazed at how often you can apply the Triple Constraint. If you have any comments, I’d love to hear them. If you liked this article, please consider subscribing to the blog via RSS or email, share it on or on Digg and pass it on to anyone that you think might appreciate it. Thank you. :)

On Deck…

I’ll be publishing posts about…

  • The next in my series of weight loss strategies
  • My next Spotlight on the web.
  • The next of my dating and relationship tips
  • More on productivity, web 2.0, social networking, family, parenting, health, and other things that you can use.

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