How to Use the Project Management Triangle to Your Advantage

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In a universe far, far away, project managers have a big budget, an unlimited amount of time, and all the resources they need for an unchanging set of project requirements.

Unfortunately, that’s not the way it works where we mere mortals reside. Instead, projects -- whether big or small -- are completed under constrained conditions.

The most common of these constraints are scope, time, and cost, which make up what is called the project management triangle.

Here, we will discuss what the project management triangle is and how project managers can use it to guide their projects.

Overview: What is the project management triangle?

The project management triangle is also known by other names, specifically iron triangle, triple constraint, project triangle, scope triangle, and quality triangle. It’s not a new concept and has been used as a tool to communicate the complexities of a project since, at the very least, the 1950s.

The project management triangle asserts that all three constraints of time, scope, and cost are interconnected, and any changes in one will affect the other two.

For example:

  • If you increase the scope of a project (e.g., add more features), you’ll have to also increase the cost or push back the deadline.
  • If you decrease the project’s budget, you’ll have to decrease the scope or extend the delivery deadline.
  • If the project’s deadline is non-negotiable, then you’ll have to either descope (e.g., create a basic prototype) or increase the budget.

A change in any of the project triangle constraints will impact one or the other two, so project managers must decide which compromises or trade-offs make the most sense for their projects and teams.

A closer look at the project management triangle

Because the inability to manage one aspect of a project will invariably affect any or both of the remaining two constraints, it makes sense to ensure that each constraint is properly managed.

Below, we take a close look at each element of the iron triangle and the best practices project managers can use for project triangle management.


In the absence of unwanted disruptions and provided conditions remain as predicted, experienced project managers are able to accurately predict how much time it will take to bring a project to completion.

However, every project manager knows that not everything goes as planned, which is why many consider the time constraint to be the most difficult to overcome.

Possible time challenges project managers must be aware of include:

  • Too much optimism: Overestimating a team’s capabilities happens all the time. It’s wise, therefore, to look at past projects, each team member’s workload, and current conditions that may affect project delivery to create a schedule that reflects reality.
  • External delays: If your project is dependent on a supplier for equipment or certain materials, a delay on their part may delay your project’s activities as well. To counter this, stay in constant communication with the vendor so they don’t overlook critical delivery dates and times.
  • Internal delays: Some tasks are sequential in nature, which means a task or activity down the line cannot begin until the preceding tasks are complete. Not only can delayed tasks disrupt the schedule, but if people or teams assigned to perform succeeding tasks can’t do anything else but sit around and wait, you are wasting money. It’s critical that you monitor dependencies closely and communicate with assigned teams constantly so everyone knows what’s going on. If needed, make the necessary adjustments, such as bringing in more people (if approved by the project’s core overseers), fast tracking certain tasks, or completing steps concurrently with other tasks.
  • Staffing gaps: Project delays happen when there are not enough skilled people working on a project. This could be because there are higher-priority projects taking up people’s time, people are getting sick, more serious workforce problems are going on (e.g., attrition), or the plan detailing the project management steps that need to be carried out is poorly crafted. Minor staffing issues can be remedied by moving tasks around or hiring outside contractors temporarily, but major staffing problems will have to involve major stakeholders, specifically the project’s change management board.
  • Unmotivated/overworked staff: Waning enthusiasm or through-the-roof absenteeism because your staff is overworked or no longer motivated is a serious problem that must be addressed ASAP. Long, ongoing projects can get tiring for some employees, while short projects may feel repetitive. To keep employees from becoming demotivated, tasks should be distributed evenly, and employees must have a solid understanding of the value their work contributes to the project overall. Communication lines must also be kept open at all times so you know how best to help your team overcome fatigue and lack of motivation.

A project that isn’t delivered on time can directly affect revenue and can be injurious to the reputation of the project manager, the team, and the organization. As such, when creating a project plan, project managers must factor buffers into their schedules to account for unexpected delays.

Techniques such as the critical path method, which evaluates the necessary critical steps to determine a project’s duration, should also help them determine must-have tasks from the "nice to have" ones.

Also, make sure a thorough feasibility study has been conducted prior to starting a project to ascertain that it’s viable and there’s enough available manpower to see it through to completion.


Projects going over budget are sometimes inevitable. Certain things simply cannot be helped, no matter how carefully you decompose the project’s plan using all the available tools (e.g., work breakdown structure diagram, PERT chart, mind map, timeline, calendar, etc.) at your disposal.

However, projects going over budget are never a good thing and should happen as infrequently as possible. Once a project has gone over budget, it’s extremely difficult to recover and complete it within budget. The best solution is still prevention.

Some factors to watch out for that could cause project budgets to fall apart include:

  • Cost underestimation: This happens when budget estimates are too optimistic, there are mistakes in the cost estimates, or the budget doesn’t take into account possible inefficiencies, such as resource scheduling conflicts or assigning work to less qualified people whose work may have to be redone.
  • Lack of accountability: Your budget may be detailed and well-thought-out, but if no one is keeping track of the expenses or making timely cost reports and budget updates, there’s still a likely chance that the project will exceed its budget. Someone has to pay close attention to the budget, whether it’s the project manager or another team member.
  • Rising personnel costs: This usually happens when new people have to be brought in to address scope creep and deadline changes. Project managers must make sure that everyone understands what’s within and out of scope right at the get-go. Outsourcing to less expensive contractors or sharing costs (e.g., research and development) with another project can also help offset costs.
  • Project delays: When projects get delayed, budgets have to be restructured to account for salaries and other overheads, extended insurances (if applicable), and litigation expenses or fines if the delay violates service level agreements.

To avoid exceeding budget allocations -- or at least minimize cost overruns -- project managers should consider adding a change or contingency budget into the project management plan to provide some cushion for unexpected events.


Your team is ready to start working on a project, the deliverables have been agreed upon, and then you get a call from one of the major stakeholders asking to “add just one tiny little thing.”

One or two additional features probably won’t hurt, but if you’re not careful, project expectations can spiral out of control, causing massive delays and ballooning costs.

Common scope challenges to be aware of include:

  • Additional feature requests: A team member wants to introduce new features they genuinely believe are beneficial to the project. Be that as it may, project managers should not allow a project to lose its focus because of feature creep. If the timeline and budget can accommodate a scope change, go ahead. Otherwise, the project manager should put their foot down and deny any more new additions.
  • Ambiguous requirements: Even clearly defined projects are known to suffer from scope creep, which means haphazardly planned projects are poised to suffer even worse consequences. Without a detailed requirements analysis and a precise decomposition of the project, the project’s scope can be misinterpreted, and scope creep can happen. Your statement of work or scope statement should outline in detail what’s within and out of scope.
  • Changing specifications: When project requirements are loosely defined, you’re opening your project up to scope creep. Last-minute changes or clients asking for additional work not originally agreed upon can lead the project down a completely different path, which will likely affect both the budget and schedule. Document everything (e.g., deliverables, timelines, milestones, budget, etc.), and ask everyone involved to sign off on them. Then, enact a change control process for changes that will affect either the budget, the timeline, or both.
  • Internal factors: Outside factors that project managers cannot control, such as competition, may affect a project’s scope. But if other sources of scope constraints, such as stakeholders wanting a new set of deliverables, threaten to derail the entire project, then the project manager must exercise their right to defend the project plan.

Benefits of using the project management triangle

There’s a reason the project management triangle is an essential component of a project manager’s toolbox. It helps project managers understand the limits of a project, which then guides them in their everyday decision-making process.

Adapt to changing conditions

Change is a factor to expect throughout the project life cycle, especially in agile project management.

The project management triangle is a reminder that projects cannot be cheap, good, and fast all at the same time, and that project managers should know where to make adjustments or compromises should change be warranted.

Communicate constraints with clients more effectively

According to research by the Project Management Institute (PMI), projects fail primarily because of poor communication, hence the importance of effective communication strategies to convey messages to team members and stakeholders. Otherwise, crucial information can fall through the cracks.

Most clients do not have a thorough understanding of the project management basics. This means that the triple constraint concept, particularly the dependencies that exist between them, is probably not something they consider when requesting an alteration in the project management plan.

The iron triangle is a visual tool you can use to illustrate the correlation, allowing them to fully understand what the changes they’re requesting entail.

The best project management software for the project management triangle

Managing the triple constraint is no cakewalk. It’s essential, therefore, that you get all the help you need, including the necessary project management tools that allow you to make the right decisions at the right time.

Below, we’ll outline certain project management software features you can leverage to manage the triple constraint.

1. TeamGantt: Gantt charts for visualization

Take a quick look at a Gantt chart and you’ll see a host of project data, such as the work scheduled for a specific day, the dependencies between tasks, how they’re tracking, the people assigned to different activities, the project’s start and end dates, each task’s duration, and completed and upcoming milestones.

Aside from intuitive, drag-and-drop Gantt charts that are crucial for project schedule and task tracking, TeamGantt also provides shared tasks lists and team calendars in one user-friendly interface.

TeamGantt's gantt char view showing a project, its steps, project owners, and estimated timeline.

TeamGantt’s Gantt chart feature lets you visualize, at a glance, how your project is tracking. Image source: Author

Other project management software systems that offer Gantt chart functionality are Microsoft Project, Wrike, Mavenlink, and Airtable.

2. Mavenlink: Budget tracking

Tracking expenses and estimating project costs is essential to keeping projects on budget. But without a tool to accurately keep track of your project’s finances, you run the risk of making costly miscalculations.

Mavenlink's built-in budget tracking and expense management feature measures actual profit margins against forecasted ones, as well as provides job/project costing and expense reporting.

Mavenlink's budget tracking line graph showing month-by-month costs for different categories.

Mavenlink’s budget tracking feature provides easy visibility into a project’s profitability. Image source: Author

Another project management software system with built-in budgeting functionality is Podio.

3. Wrike: Resource planning

Making sure that your project team delivers on its day-to-day workload is not an easy responsibility to pull off without a resource tracking tool that gives you visibility into the work team members perform every day.

Wrike's resource management dashboard showing assignments, assignees, timeline, and a tooltip showing details of each assignment.

Wrike Resource is an add-on with robust resource planning and scheduling features that you can use to assign work and track each team member’s workload. Image source: Author

Wrike allows you to optimize work distribution. In other words, the system helps you assign and schedule work across the team in the most efficient way possible. You know who’s working on which task so you can make adjustments accordingly.

Keeping projects successful amid constraints

All projects will have constraints, but they should not be seen as barriers to successful project execution. Instead, a good project manager will use the project triangle to understand the limits of a project.

Ultimately, unawareness of the dependencies between constraints can result in wrong decisions that will negatively impact how a project develops.

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