Depending on whom you ask, there are many, different "project management" shapes: triangles, diamonds, stars. And each shape portrays a slightly (or considerably) different idea of the factors that can influence and constrain a project. Even the basic project management triangle has several close-but-different versions. For the sake of this article, let's assume that the project management triangle is cost (the amount of money available), time (the amount of time available) and quality (the level of excellence desired). That is, these are the three basic constraints for your project.
The area of the triangle formed by the three project constraints represents the scope of the project (i.e., the amount of project work you can get done for a given cost, over a given time and at a certain level of quality). Balancing your project constraints -- finding the "sweet spot" between them all -- helps maximize your scope. However, balance can be difficult to achieve. A direct change to one constraint will often result in an indirect change to one of the others, but not always. A change to one constraint might affect both other constraints or have no effect on the others.
So the question is, "How do we adjust our constraints to define the optimal project scope?" A complete answer would be too complex to fit in this short article in any meaningful way, but below are a few ideas to lead you in the right direction.
First, you should determine which of your constraints are fixed (unchangeable) and which are variable (changeable). It is rare that all three constraints are fixed. But, if they are, you're wasting time reading this article. You already know your boundaries.
More often, only one or two constraints are fixed. Fixed-price contracts, where the project budget is predetermined, are common. Similarly, some projects will have a contractual deadline that must be met, which fixes the project schedule. And some projects must attain a certain level of excellence, no matter the time or cost, which establishes a fixed project quality constraint.
Once you've determined if any of your constraints are fixed, you can shift focus to the other, variable constraints. Do consider the fixed constraints, but dwelling on them would be a waste of time.
When looking at the variable constraints, consider them in terms of their effect on other constraints. For example, does increasing or reducing the budget adjust your deadline; does it affect the level of quality you expect to deliver? Answering such questions will help determine whether changing a variable constraint will help or hurt.
There are many, many things to do and consider when changing a variable constraint. But chief among them is talking with your customer. Find out what is most important to the customer and which aspects of the project are valued most. These factors will help determine which variable constraints you can (and should) change, and what the effects of the change will be. The ultimate goal is to have three project constraints that are in accordance with the customer's desires and that give you an achievable project scope.
As long as you have variable constraints, you have options. And by talking with the customer, you can determine the best, balanced option to find an achievable project scope -- one that is on time, within budget and of high quality.
Quiz: Project management
Project management trends -- Rapid changes to project management