Cost, time and scope

4 min readDec 5, 2020

In order to understand the life cycle of a project, it is necessary to understand three key concepts that are the key for a project that starts and finish successfully: cost, time and scope.

Before getting to the point of defining why each of these elements is important, as well as their set, it is necessary to explain each one separately.


The cost of a project is a collection of all the resources that are necessary to carry out the project.

The cost includes fixed expenses, variable expenses, intangibles and any element that requires an investment by the creditors of the project, the executors or the managers.

In this case, time is also a form of cost, however a substantial separation is made, because time is a more complex variable in the life cycle of a project than only as a cost.


The time of a project is the measurable number of years, months, days, weeks, hours the project can take, from start to finish.

It is important to know this variable from the beginning because its importance in the operation of the project is key, there are elements such as opportunity costs, work windows or even external elements that can make not being within the established time parameters, lead to a project to failure.


The scope is the definition of why a project is carried out, what is the expected final result and breaking down that result into small temporary elements that are part of that puzzle that in the end will be the completed project.

An important challenge in each project is to maintain a fixed scope throughout the course of the project, since while the results or problems are occurring, it is tempting to change the objective.

CTA (Cost, Time and Scope)

These three elements must be taken into account for any decision process in the project, since these are the equivalent of the values ​​of a person, the mission of a company.

It is the compass under which a project manager should be guided in order to make decisions and how to report the progress of the project.

To start, and one of the clearest examples, is in change management.

When a change is requested to an element of the project, what has to be done immediately is an evaluation of cost, time and scope, to know the impact and based on this make an informed decision regarding whether or not to proceed. Even when the decision to change does not correspond directly to the project manager, presenting the impact in terms of cost, time and scope to the project’s creditors will make the decision easier to make.

You should think about the cost, time and scope, as if they were defined borders within the project for which specific requirements are required to cross or even redefine.

At the beginning of the project there is a projected cost, if a modification is to be made in time, it must be taken into account if this is going to affect cost and scope, in the same way as if the scope is to be modified you have to take into account how it will affect cost and time.

Photo by Markus Winkler on Unsplash


In project management, decision-making is the key to keeping a project on track, and many times these decisions have to be made quickly and with little information.

When managing a project, you must have these well-defined borders, what are the expected costs, how long the project will take to complete and what will be achieved in the end.

For the project manager, any element that happens on a day-to-day basis that may cross those borders or may detect a trend that will take the project out of any of those borders is when it must act with contingency plans.


There are cases in which a project cannot sustain these boundaries, that is, it is inevitable that the cost, time or scope will be modified, so you have to have two main things.

  • A clear and prior vision that this is going to happen, since preparation is everything in projects, if an incident leads to these elements being exceeded from one day to the next, it is almost certain that the project will get out of control.
  • Have a way of how to solve the impact, in a few words how to cover the cost, how to solve the time and if the scope is really as desired.

Life cycle of a project

The definition of the cost, time and scope for a project manager has to be one of the first activities that must be carried out.

In case any of the terms are not clear, he should seek the answers with the creditors of the project or even with the execution team so that all the rules are clear before starting the project.

Once the cost, time and scope of the project have been established, this must be the lodestar for the project manager, because if any of these fail, it is very difficult for the project to be called successful.

On the other extreme, a project manager who keeps a project on time, cost, and scope, can say they have a successful project on their hands.




I strongly believe that project management is key in life as it is in business. It help us achieve our goals and maintain a balanced life.