It doesn't matter what industry you're in, how experienced you are, how "different" your project
is, or what version of project management methodology your organization uses. At every project's core is the trio of time, money, and scope (scope: The combination of all project goals and tasks, and the work required to accomplish them.). These are the factors you juggle every day to keep your Project plan on track.
In this article
What is the project triangle?
If time, money, or what your project accomplished were unlimited, you wouldn't need to do project management.
Unfortunately, most projects have a specific time limit,
budget (budget: The estimated cost of a project that you establish in Project with your baseline plan.), and scope.
It is this combination of elements
(time, money,
and scope) that we refer to as the project triangle. (These competing elements are sometimes referred to as the triple constraints of a project.) Understanding the project
triangle will allow you to make better choices when you need to make
tradeoffs.

If
you adjust any one side of the triangle, the other two sides are affected.
For example, if you decide to adjust the project plan (plan: A schedule of task start and finish dates and resource and cost data. A baseline plan is the original plan that you save and use to monitor progress. An interim plan is a set of dates you save during the project to compare to other interim plans.) to:
- Bring
in the scheduled
finish date (finish date: The date that a task is scheduled to be completed. This date is based on the task's start date, duration, calendars, predecessor dates, task dependencies, and constraints.), you might end up with
increased costs (cost: The total scheduled cost for a task, resource, or assignment, or for an entire project. This is sometimes referred to as the current cost. In Project, baseline costs are usually referred to as "budget.") and a decreased scope.
- Meet the project budget, the result might be a longer schedule and
a decreased scope.
- Increase scope, your project might take more
time and cost more money in the form of resources (resources: The people, equipment, and material that are used to complete tasks in a project.), such as workers.
Changes to your plan can affect the
triangle in various ways, depending on your specific circumstances and the
nature of your project. For example, in some instances, shortening your
schedule might increase costs. In other instances, it might actually decrease
costs.
In terms of the project triangle,
resources are considered a cost item. So
as you adjust resources to accommodate more or less work or to reflect their
availability, your costs go up or down correspondingly. These costs are based
on resource pay rates (pay rate: Resource cost per hour. Project includes two types of pay rates: standard rates and overtime rates.).
You also
may notice that as you adjust resources, your schedule changes. For example, if
you have a number of resource overallocations (overallocation: The result of assigning more tasks to a resource than the resource can accomplish in the working time available.) and you
level (leveling: Resolving resource conflicts or overallocations by delaying or splitting certain tasks. When Project levels a resource, its selected assignments are distributed and rescheduled.) the project, the schedule might now
include split tasks (split task: A task whose schedule is interrupted. For example, a two-day task that does not require contiguous work might be split so that the first day of work is scheduled for Monday, and the second day is scheduled for Thursday.) and
delays (delay: The amount of time between the scheduled start of a task and the time when work should actually begin on the task; it is often used to resolve resource overallocations. There are two types of delay: assignment delay and leveling delay.) that extend the finish date.
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Where's the stuck side of the
triangle?
Did you say "stuck side"? That's right. In most
projects, at least one side of the triangle is stuck, meaning you're stuck,
because you can't change it. On some projects, it's the budget. No matter what,
you won't get more money for the project. On others, it's the schedule—the
dates can't change. Or it's the scope—there will be no change in deliverables (deliverable: A tangible and measurable result, outcome, or item that must be produced to complete a project or part of a project. Typically, the project team and project stakeholders agree on project deliverables before the project begins.).
The trick is in finding the the "stuck" or fixed sides of your
project's triangle. That tells you what you can change and where to adjust if
there's a problem. Phrasing the problem as a statement can help you clarify
which side of the triangle is in trouble.
Knowing which side of
your triangle can't be changed will help you know where to adjust. So when you
begin optimizing:
- First, decide which of the
three elements is fixed. This is typically the element most important to the
success of your project (finishing on time, on budget, or with the agreed-upon
scope).
- Then, determine which side your current problem occurs on.
Once you've done that, you'll know what elements you have to work with to get
your project back on track.
If the
problem side and the fixed side are the same, you have the remaining two sides
of the triangle to work with. For example, if your project has to finish on
time and your problem is that it's taking too long, you can adjust resources or
adjust scope to get the project back on track.
If the problem side
is different than the fixed side, you'll want to optimize by adjusting the
remaining side. For example, if your project has to finish on time and it's
grown in scope, you only have the cost side to play with by, for instance, by
adding resources.
Know that when you adjust one side of the
triangle of time, money, and scope, the other two sides are likely to be
affected. They can be affected positively or negatively, depending on the
nature of your project.
Note After adjusting your project plan,
check the other two elements again to make sure nothing has become unworkable.
For example, if you adjusted your plan to bring in costs, check to see if your
finish date is still acceptable.
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How do I optimize to meet my schedule?
After analyzing
your schedule, you might find it does not meet the project deadline. There are
several ways you can adjust the length of your schedule. The methods you choose
depend on the limitations imposed on the project as a whole, such as budget,
resource availability (availability: Indicates when and how much of a resource's time can be scheduled for assigned work. Availability is determined by project and resource calendars, resource start and finish dates, or the level at which the resource is available for work.), scope, and the
flexibility of the tasks.
The most efficient way to shorten the
schedule is to change the tasks that lie on the critical path (critical path: The series of tasks that must be completed on schedule for a project to finish on schedule. Each task on the critical path is a critical task.). The critical path is a series
of dependent tasks whose last task finishes at the project end date. If any of
the tasks in this series move, the project end date also moves. Modifying tasks
that are not on the critical path may not affect the schedule. You
can:
As you adjust the schedule, your costs might
increase, resources might become overallocated, and your scope might change.
For example, if you shorten durations of tasks on the critical path, the
project will probably finish sooner, but the scope of those tasks and possibly
the entire project might be reduced. Or if you assign additional resources to
critical path tasks so that they can be finished more quickly, you might find
that these resources are now overallocated, and you need to pay
overtime (overtime: The amount of work on an assignment that is scheduled beyond the regular working hours of an assigned resource and charged at the overtime rate. Overtime work indicates the amount of the assignment's work that is specified as overtime work.), increasing your
costs.
Learn more about how to optimize the schedule using the The Project Road Map.
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How do I optimize to meet my
budget?
You might find that the Project plan you have
built exceeds your budget. Project costs are affected primarily by resources
assigned to the tasks in the project: the rate-based cost and the
fixed costs (fixed cost: A set cost for a task that remains constant regardless of the task duration or the work performed by a resource.) of people, equipment, and
materials. Therefore, to reduce costs, you can cut project scope so that there
are fewer tasks or shorter durations for tasks that need
resources.
If you don't want to cut scope, you can adjust resources
and make sure that your settings for rates, fees, and overtime are correct. You
can verify that the resources assigned are the best for the job. You might be
able to replace a more expensive resource with a less expensive one, and use
the more expensive resource where it is most cost-effective.
As you
adjust the plan to meet your budget, your finish date might be extended, or the
scope might decrease. For example, if you remove overtime from tasks that had
overallocated resources assigned, you might find the schedule lengthened to the
point where the finish date is a month later. Or if you've cut scope to meet
the budget, you might find that the finish date is actually scheduled to occur
sooner.
Learn more:
Learn how to create a budget for your project.
Learn how to optimize the schedule using the The Project Road Map.
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How do I optimize to meet my
scope requirements?
There are two aspects of scope to
consider—product scope and project scope:
- Product scope describes the final deliverables of the
project, usually in great detail. Examples of product scope include product
specifications or blueprints. As a project manager, you may not have much
control over product scope.
- Project scope includes all of the
project work done to produce the deliverables described by the product scope.
As a project manager, you normally have at least some control over project
scope. For example, you may be able to skip code reviews for some deliverables.
Typically, you adjust scope when
you find a problem with meeting the finish date or the budget. You can cut
scope to bring in the finish date or cut costs. You can also increase scope if
you find you have additional time or an increased budget
available.
Changing scope usually involves changing the number or
the duration of tasks. Scope is closely related to quality (quality: The degree of excellence, or the desired standards, in a product, process, or project.). When you increase scope, you have the
opportunity to build in higher quality. When you decrease scope, you might need
to lower standards of acceptable quality.
If you reduce scope, your
costs might decrease and your finish date might occur sooner. If you add scope,
your costs might increase and your finish date might be later. For example, if
you cut a series of tasks that were considered optional, you may not need as
many resources, resulting in cost savings. Or if you're increasing scope by
adding more time to a series of tasks, you might find that changing scope
affects the scheduling of critical path tasks, and the finish date is now two
weeks later.
Learn more about how to optimize the schedule using the The Project Road Map.
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What does quality have
to do with the project triangle?
Quality is at the center of the
project triangle. Quality affects every side of the triangle,
and any changes
you make to any side of the triangle are likely to affect quality. Quality is
not a factor of the triangle; it is a result of what you do with time, money,
and scope.

For
example, if you find you have additional time in your schedule, you might be
able to increase scope by adding tasks and duration. With this extra time and
scope, you can build a higher level of quality into the project and its
deliverables.
Or if you need to cut costs to meet your budget, you
might have to decrease scope by cutting tasks or reducing task durations. With
decreased scope, there might be fewer opportunities to achieve a certain level
of quality, so a lower quality results from the need to cut costs.
Learn more about how to manage the project triangle:
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